Understanding metastatic involvement of the conus medullaris: a systematic review of clinical presentations, diagnostic approaches, treatment options, and patient outcomes.

INTRODUCTION: Metastasis to the conus medullaris (CM) is a rare but devastating condition. This systematic review aimed to evaluate the clinical presentation, diagnostic workup, treatment options, and outcomes of patients with CM metastasis. By synthesizing the available evidence, this study seeks to improve our understanding of this condition and inform clinical practice. MATERIALS AND METHODS: A systematic review adhering to PRISMA guidelines analyzed literature on CM metastasis from 1997 to January 2024. Human studies in English were included, focusing on primary research articles. Screening criteria ensured a homogeneous study population, with data analyzed using SPSS 26 and assessed for quality using the JBI checklist. RESULTS: The study analyzed 88 patients with conus medullaris metastasis. Common symptoms included back pain (49.3%), sensory impairment (75%), and bladder dysfunction (60.3%). MRI was the primary diagnostic tool, revealing lesions above L1 (37%) or between L1 and L2 (29%). Treatment involved surgery with laminectomy, and combined therapy (surgery plus radiotherapy) in 81.3%. Postoperative outcomes showed improved motor function in 59.6% of patients, while combined therapy yielded better sensory and bowel/bladder function recovery. Median survival was 100 days. CONCLUSION: Metastasis to the conus medullaris is rare but significant. Surgical resection can improve motor function, while combined therapy (surgery plus radiotherapy) is effective in improving sensory manifestations and bowel/bladder functions. Despite these treatments, the median survival remains around 100 days, which is shorter compared to other types of intramedullary spinal cord metastases.

The neurosurgeon's familiarity with the vein of Rolando.

The vein of Rolando, also known as the central sulcal vein, is a critical superficial cerebral vein located in the central sulcus, playing a pivotal role in the venous drainage of the motor and sensory cortices. Named after the Italian anatomist Luigi Rolando, this vein serves as a crucial anatomical landmark in neurosurgery, guiding surgeons to approach critical brain structures with minimal damage. This article explores the anatomy and clinical significance of the vein of Rolando, emphasizing its role in neurosurgery and neuroimaging. Advanced imaging techniques such as functional MRI (fMRI), Magnetic Resonance Venography (MRV), and CT Angiography have enhanced the ability to diagnose and preserve this vein, reducing surgical risks. The article also discusses the interconnectedness of the vein of Rolando with other cerebral veins like the vein of Trolard and underscores the importance of understanding venous variations and drainage patterns for successful surgical outcomes. Preventive measures to protect the vein during neurosurgery are essential to prevent complications such as venous congestion and intracranial pressure. This overview highlights the necessity for precise anatomical knowledge and advanced diagnostic tools in optimizing neurosurgical procedures and patient care.

Treatment strategies for saccular anterior inferior cerebellar artery aneurysms: a systematic review.

INTRODUCTION: The anterior inferior cerebellar artery (AICA) plays a crucial role in cerebellar blood supply, and AICA aneurysms are relatively rare, comprising less than 1-1.5% of all brain aneurysms. Understanding their clinical scenarios, management approaches, and outcomes is essential. This systematic review analyzes data from 86 studies to comprehensively explore AICA aneurysms. MATERIALS AND METHODS: The process of obtaining relevant research, which includes patients with AICA aneurysms, was carried out using the PubMed, Web of Science, and Scopus databases. This review exclusively included extensive papers written in English. The search included the MeSH phrases "Anterior inferior cerebellar artery aneurysm" and "AICA aneurysm." Microsurgical and endovascular treatments were compared using statistical analysis, exploring demographics, risk factors, treatment modalities, and clinical outcomes. RESULTS: The review includes 85 case reports and one retrospective study, totaling 140 patients. The study reveals a diverse patient profile with a slight female predominance (65%), a mean age of 50.7 years, and an 82.86% prevalence of no identified risk factors. Ruptured aneurysms accounted for 55%, with microsurgery and endovascular procedures accounting for 70.71% and 27.86%, respectively. The mortality rate was 2.86%, and no significant differences were found in rebleed, recurrence, or mortality rates between treatment groups. CONCLUSION: Microsurgical and endovascular interventions demonstrate comparable effectiveness, with microsurgery showing superiority in specific situations. Therefore, tailoring treatment is crucial to individual patient needs. Subgroup analyses highlight demographic-specific trends, guiding clinicians in managing this rare pathology.

A cross-sectional study on infectious health risks regarding freshwater sports practice in Brittany, France.

Freshwater sports expose practitioners to pathogens in the water environment and may result in infection. In French Brittany, these infections are particularly worrying, especially since 2016 with an increase in the incidence of leptospirosis reaching 1 case per 100,000 inhabitants, which represents the highest incidence observed since 1920. We aimed to estimate the prevalence of infectious diseases related to freshwater sports practice and to identify the factors associated with these infections among freshwater sports licensees in Brittany, France. From March 18, 2019, to May 8, 2019, we interviewed freshwater sports licensees (online study) and club presidents and instructors (phone study) in Brittany. Licensee participants were 18 years old or more and practiced at least one freshwater sport in one of the 79 Brittany clubs. We used logistic regression models to study the association between our variables of interest and potential risk factors. In total, 551 licensees (20.3% of the total number of licensees) and 38 clubs (48.1%) were surveyed. Among the licensees, 29 (5.3%) reported being diagnosed with leptospirosis, of which 12 (41.3%) occurred in the last 5 years. The most reported symptoms were skin irritation/itchy skin (24.3%) and 39 individuals (7.1%) reported at least one hospitalization in their lifetime for a disease related to freshwater sports. The occurrence of leptospirosis was negatively associated with boarding from a pontoon (odds ratio (OR)=0.20, 95% confidence interval (95% CI) 0.06-0.56), practicing for less than 4 years (OR=0.17, 95% CI 0.04-0.56) compared to more than 10 years, and the occurrence of leptospirosis was positively associated with taking a soapy shower after practice (OR=4.38, 95% CI 1.90-10.51). Eskimo roll was positively associated with the occurrence of otitis and conjunctivitis (OR=3.22, 95% CI 1.82-6.03), and skin irritation/itchy skin (OR=1.66, 95% CI 0.99-2.84). Otitis, conjunctivitis, and skin irritation/itchy skin are the most commonly reported freshwater sport-related diseases in French Brittany. Despite a good level of knowledge of prevention measures, their implementation by licensees and clubs remains low. Further studies are needed to identify practices associated with infectious risk in freshwater sports.

Water, sanitation and hygiene interventions and the prevention and treatment of childhood acute malnutrition: A systematic review.

Undernutrition is more prevalent among children living in unsanitary environments with inadequate water, sanitation and hygiene (WASH). Despite good evidence for the effect of WASH on multiple infectious diseases, evidence for the effect of WASH interventions on childhood undernutrition is less well established, particularly for acute malnutrition. To assess the effectiveness of WASH interventions in preventing and treating acute childhood malnutrition, we performed electronic searches to identify relevant studies published between 1 January 2000 and 13 May 2019. We included studies assessing the effect of WASH on prevention and treatment of acute malnutrition in children under 5 years of age. Data were extracted by two independent reviewers. We included 26 articles of 599 identified references with a total of 43,083 participants. Twenty-five studies reported on the effect of WASH on prevention, and two studies reported its effect on treatment of acute malnutrition. Current evidence does not show consistent associations of WASH conditions and interventions with prevention of acute malnutrition or with the improvement of its treatment outcomes. Only two high-quality randomized controlled trials (RCTs) demonstrated that improved water quality during severe acute malnutrition treatment improved recovery outcomes but did not prevent relapse. Many of the interventions consisted of a package of WASH services, making impossible to attribute the effect to one specific component. This highlights the need for high-quality, rigorous intervention studies assessing the effects of WASH interventions specifically designed to prevent acute malnutrition or improve its treatment.

Optimization of the Duration and Intensity of UV-A Radiation to Obtain the Highest Free Phenol Content and Antioxidant Activity in Sprouted Sorghum (Sorghum bicolor L. Moench).

Technologies such as UV-A radiation applied to sprouted sorghum can stimulate the synthesis or release of phenolic compounds. Since the optimal conditions for stimulating the formation of these compounds in sorghum sprouts are unknown, we used the response surface methodology to identify the optimal conditions of irradiation duration and intensity to obtain the highest free phenol content and antioxidant activity in sprouted sorghum. The results showed that, compared with nonirradiated sorghum sprouts, sprouts irradiated under the optimal duration of 11.7 h and the optimal intensity of 5.4 µW/cm2 had a significantly higher phenol content (26.3%) and antioxidant activity as measured by DPPH (28.3%) and TEAC (21.1%) assays. Our findings suggest that UV-A radiation can help develop sorghum sprouts with high biological potential that can be used to produce healthy foods for human consumption.

Entrenchment: effects of multiple red herrings on memory blocks in word fragment completion.

Two experiments examined blocking and entrenchment using a word fragment completion task. After incidental priming tasks in which varying numbers of red herring stimuli (i.e., wrong answers to subsequent problems) were seen, word fragment completion was tested for items orthographically similar to primed words. Both experiments showed a memory blocking effect, poorer fragment completion when any red herrings had been seen, relative to a control (zero red herrings) condition. An entrenchment effect, poorer performance when more red herrings were primed, was also observed. Both experiments show that entrenchment effects occur with indirect measures of memory, and these results have implications for fixation effects in problem solving.

Reconversion of neurosurgical practice in times of the SARS-CoV-2 pandemic: a narrative review of the literature and guideline implementation in a Mexican neurosurgical referral center.

OBJECTIVE: The coronavirus disease 2019 (COVID-19) pandemic has forced the modification of surgical practice worldwide. Medical centers have been adapted to provide an efficient arrangement of their economic and human resources. Although neurosurgeons are not in the first line of management and treatment of COVID-19 patients, they take care of patients with neurological pathology and potential severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Here, the authors describe their institutional actions against the pandemic and compare these actions with those in peer-reviewed publications. METHODS: The authors conducted a search using the MEDLINE, PubMed, and Google Scholar databases from the beginning of the pandemic until July 11, 2020, using the following terms: "Neurosurgery," "COVID-19/SARS-CoV-2," "reconversion/modification," "practice," "academy," and "teaching." Then, they created operational guidelines tailored for their institution to maximize resource efficiency and minimize risk for the healthcare personnel. RESULTS: According to the reviewed literature, the authors defined the following three changes that have had the greatest impact in neurosurgical practice during the COVID-19 pandemic: 1) changes in clinical practices; 2) changes in the medical care setting, including modifications of perioperative care; and 3) changes in the academic teaching methodology. CONCLUSIONS: The Instituto Nacional de Neurología y Neurocirugía "Manuel Velasco Suárez" is one of the major referral centers for treating highly complex neurosurgical pathologies in Mexico. Its clinical and neurosurgical practices have been modified with the implementation of specific interventions against the spread of COVID-19. These practical and simple actions are remarkably relevant in the context of the pandemic and can be adopted and suited by other healthcare centers according to their available resources to better prepare for the next event.

A computational model of ESAT-6 complex in membrane.

One quarter of the world's population are infected by Mycobacterium tuberculosis (Mtb), which is a leading death-causing bacterial pathogen. Recent evidence has demonstrated that two virulence factors, ESAT-6 and CFP-10, play crucial roles in Mtb's cytosolic translocation. Many efforts have been made to study the ESAT-6 and CFP-10 proteins. Some studies have shown that ESAT-6 has an essential role in rupturing phagosome. However, the mechanisms of how ESAT-6 interacts with the membrane have not yet been fully understood. Recent studies indicate that the ESAT-6 disassociates with CFP-10 upon their interaction with phagosome membrane, forming a membrane-spanning pore. Based on these observations, as well as the available structure of ESAT-6, ESAT-6 is hypothesized to form an oligomer for membrane insertion as well as rupturing. Such an ESAT-6 oligomer may play a significant role in the tuberculosis infection. Therefore, deeper understanding of the oligomerization of ESAT-6 will establish new directions for tuberculosis treatment. However, the structure of the oligomer of ESAT-6 is not known. Here, we proposed a comprehensive approach to model the complex structures of ESAT-6 oligomer inside a membrane. Several computational tools, including MD simulation, symmetrical docking, MM/PBSA, are used to obtain and characterize such a complex structure. Results from our studies lead to a well-supported hypothesis of the ESAT-6 oligomerization as well as the identification of essential residues in stabilizing the ESAT-6 oligomer which provide useful insights for future drug design targeting tuberculosis. The approach in this research can also be used to model and study other cross-membrane complex structures.

Revealing the mechanism of SARS-CoV-2 spike protein binding with ACE2.

A large population in the world has been infected by COVID-19. Understanding the mechanisms of Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) is important for management and treatment of the COVID-19. When it comes to the infection process, one of the most important proteins in SARS-CoV-2 is the spike (S) protein, which is able to bind to human Angiotensin-Converting Enzyme 2 (ACE2) and initializes the entry of the host cell. In this study, we implemented multi-scale computational approaches to study the electrostatic features of the interfaces of the SARS-CoV-2 S protein Receptor Binding Domain (RBD) and ACE2. The simulations and analyses were performed on high-performance computing resources in Texas Advanced Computing Center (TACC). Our study identified key residues on the SARS-CoV-2, which can be used as targets for future drug design. The results shed lights on future drug design and therapeutic targets for COVID-19.

[Primary Tumors of the Central Nervous System. Clinical Experience at a Third Level Center].

Background: Central nervous system (CNS) tumors are a group of neoplasms that originate from various cells in the CNS. The increasing incidence and prevalence of this type of tumor in developing countries are striking; however, there are few current studies in Latin America including Mexico estimating the impact of these pathological entities on the general population. Objective: The objective of the study was to study the characteristics of primary CNS tumors over a period of 52 years. Methods: A review of records from patients with a histopathological diagnosis of CNS neoplasm over a period of 52 years was conducted at a tertiary-care academic medical center. Patients were grouped by sex, age, and the tumor's anatomical location. Results: A sample of 9615 patients with tumor lesions was obtained; 51% were female, 49% were male, and their mean age was 42 years. The tumors with the highest prevalence were neuroepithelial tumors (38.6%), followed by meningeal tumors (22.8%). Neuroepithelial tumors accounted for 64% in the group of patients under 40 years of age and 56% among those above 40 years of age. The most frequently involved location was supratentorial, in 78.9% of cases. Conclusions: Although retrospective in nature and based on a small sample, this study reports the epidemiology and characteristics of primary brain tumors in the Mexican population.

[Auto-expandable metal stent in the management of distal stomach cancer]. / Experiencia con los stents metálicos autoexpandibles para el manejo de cáncer gástrico distal.

OBJECTIVES: To establish the efficacy and safety of antroduodenal metal stents for the treatment of pyloric syndrome in patients with distal gastric cancer. MATERIALS AND METHODS: Data were obtained from 31 patients older than 18 years who had a diagnosis of distal gastric cancer between 2009 and 2017, who presented pyloric syndrome associated with antroduodenal stenosis documented by endoscopy or X-ray of upper digestive tract, being managed with an antroduodenal auto-expandable metal stent in the gastroenterology unit of the San Ignacio University Hospital (HUSI) in Bogotá DC, Colombia. RESULTS: The main documented symptom that led to consultation was the presence of vomiting in 45.1%, followed by weight loss 16.13% and upper digestive tract bleeding 19.35%, the diagnosis being made in 74.19 % of cases with endoscopy of upper digestive tract. 96.7% of the patients presented metastases at the time of diagnosis of pyloric syndrome. 100% of patients had technical success in relation to stenting with subsequent resolution of symptoms in 96.77%, the most frequent complication being displacement in 16.13%. CONCLUSIONS: Auto-expandable metal stents for the management of gastric outlet tract obstruction secondary to distal gastric cancer is a safe and effective method as a palliative treatment, improving morbidity and mortality compared to surgical management.

An In-Depth Analysis of the Artery of Salmon: Anatomy and Neurosurgical Implications.

BACKGROUND: Michel Salmon was a prominent person in the field of plastic surgery during the early 20th century. His pioneering work contributed significantly to our understanding of human anatomy, particularly with the identification of the artery of Salmon (AOS). The objective of this study is to thoroughly investigate the AOS by conducting a comprehensive literature review, providing insights into its anatomy and surgical implications. METHODS: This review was undertaken after a thorough examination of literature encompassing papers about the AOS. Right up until January 2024, databases like PubMed, ScienceDirect, and Web of Science were explored. The search was conducted using specific terms such as "Artery of Salmon," "suboccipital artery," and "vertebral artery anatomy." An in-depth assessment was conducted to examine the anatomy, and surgical significance of the AOS. RESULTS: The AOS is a branch of the V3 segment of the vertebral artery that supplies the suboccipital muscles. The ability, to identify it, is critical for distinguishing the origins of intraoperative hemorrhage. Through careful surgical intervention, the artery was able to devascularize tumors and vascular lesions. We also touched on the technical issues of its possible application in bypass operations for aneurysms of the posterior inferior cerebellar artery or vertebral artery. CONCLUSIONS: The AOS is sometimes vital in neurosurgery, facilitating precise interventions and serving as a conduit in suboccipital bypass surgeries. Understanding its variations is essential for neurosurgeons, showcasing ongoing advancements in patient care.

High Accuracy of Three-Dimensional Navigated Kirschner-Wire-Less Single-Step Pedicle Screw System (SSPSS) in Lumbar Fusions: Comparison of Intraoperatively Planned versus Final Screw Position.

(1) Background: Our team has previously introduced the Single-Step Pedicle Screw System (SSPSS), which eliminates the need for K-wires, as a safe and effective method for percutaneous minimally invasive spine (MIS) pedicle screw placement. Despite this, there are ongoing concerns about the reliability and accuracy of screw placement in MIS procedures without traditional tools like K-wires and Jamshidi needles. To address these concerns, we evaluated the accuracy of the SSPSS workflow by comparing the planned intraoperative screw trajectories with the final screw positions. Traditionally, screw placement accuracy has been assessed by grading the final screw position using postoperative CT scans. (2) Methods: We conducted a retrospective review of patients who underwent lumbar interbody fusion, using intraoperative 3D navigation for screw placement. The planned screw trajectories were saved in the navigation system during each procedure, and postoperative CT scans were used to evaluate the implanted screws. Accuracy was assessed by comparing the Gertzbein and Robbins classification scores of the planned trajectories and the final screw positions. Accuracy was defined as a final screw position matching the classification of the planned trajectory. (3) Results: Out of 206 screws, 196 (95%) were accurately placed, with no recorded complications. (4) Conclusions: The SSPSS workflow, even without K-wires and other traditional instruments, facilitates accurate and reliable pedicle screw placement.

Characterization of a model of liver regeneration: Role of hedgehog signaling in experimental hepatic amoebiasis.

The development of amoebic liver abscess (ALA) leads to liver necrosis, accompanied by an exacerbated inflammatory response and the formation of multiple granulomas. Adequate management of the infection through the administration of treatment and the timely response of the organ to the damage allows the injury to heal with optimal regeneration without leaving scar tissue, which does not occur in other types of damage such as viral hepatitis that may conducts to fibrosis or cirrhosis. The Hedgehog signaling pathway (Hh) is crucial in the embryonic stage, while in adults it is usually reactivated in response to acute or chronic injuries, regeneration, and wound healing. In this work, we characterized Hh in experimental hepatic amoebiasis model, with the administration of treatment with metronidazole, as well as a pathway inhibitor (cyclopamine), through histological and immunohistochemical analyses including an ultrastructure analysis through transmission electron microscopy. The results showed an increase in the percentage of lesions obtained, a decrease in the presence of newly formed hepatocytes, a generalized inflammatory response, irregular distribution of type I collagen accompanied by the presence of fibroblast-type cells and a decrease in effector cells of this pathway. These results constitute the first evidence of the association of the activation of Hh with the liver regeneration process in experimental amebiasis.

Predictors of poor functional outcomes in adults with type I Chiari Malformation: Clinical and surgical factors assessed with the Chicago Chiari Outcome Scale over long-term follow-up.

OBJECTIVE: This study aimed to identify clinical and surgical features associated with poor long-term postoperative outcomes in patients diagnosed with Type I Chiari Malformation (CMI) treated with posterior fossa decompression with duroplasty (PFDD), with or without tonsillar coagulation. METHODS: This retrospective, single-center study included 107 adult patients with CMI surgically treated between 2010 and 2021. The surgical technique involved a midline suboccipital craniectomy, C1 laminectomy, durotomy, arachnoid dissection, duroplasty, and tonsillar coagulation until 2014, after which tonsillar coagulation was discontinued. Postoperative outcomes were assessed using the Chicago Chiari Outcome Scale (CCOS) at a median follow-up of 35 months. Clinical, surgical, and neuroimaging data were analyzed using the Wilcoxon signed-rank test, Cox regression analysis, and Kaplan-Meier survival curves to identify predictors of poor functional outcomes. RESULTS: Of the 107 patients (mean age 43.9 years, SD 13), 81 (75.5 %) showed functional improvement, 25 (23.4 %) remained unchanged, and 1 (0.9 %) experienced worsened outcomes. Cephalalgia, bilateral motor weakness, and bilateral paresthesia were the most frequent initial symptoms. Tonsillar coagulation was performed in 31 cases (28.9 %) but was clinically associated with higher rates of unfavorable outcomes. The Wilcoxon signed-rank test indicated that long-term follow-up CCOS was significantly higher than postoperative CCOS (Z = -7.678, p < 0.000). Multivariate Cox analysis identified preoperative bilateral motor weakness (HR 6.1, 95 % CI 1.9-18.9; p = 0.002), hydrocephalus (HR 3.01, 95 % CI 1.3-6.9; p = 0.008), and unilateral motor weakness (HR 2.99, 95 % CI 1.1-8.2; p = 0.033) as significant predictors of poor outcomes on a long-term follow-up. CONCLUSION: This study highlights the high rate of functional improvement in CMI patients following PFDD. Preoperative motor weakness and hydrocephalus were significant predictors of poor long-term outcomes. Tonsillar coagulation did not demonstrate a clear clinical benefit and may be associated with worse outcomes. Our findings suggest that careful preoperative assessment and selection of surgical techniques are crucial for optimizing patient outcomes.

Phosphorylation of Tyrosine 841 Plays a Significant Role in JAK3 Activation.

Janus Kinase 3 (JAK3) plays a key role in the development, proliferation, and differentiation of various immune cells. It regulates gene expression by phosphorylation of Signal Transducers and Activators of Transcriptions (STATs) via the JAK/STAT pathway. Recently, we found a new JAK3 phosphorylation site, tyrosine 841 (Y841). The results showed that pY841 helps the kinase domain flip around the pseudo kinase domain, which may cause JAK3 conformational changes. It also reduces the size of the cleft between the N-lobe and the C-lobe of the JAK3 kinase domain. However, pY841 was found to enlarge the cleft when ATP/ADP was bound to the kinase. The increase in the cleft size suggested that pY841 enhanced the elasticity of the kinase domain. For unphosphorylated JAK3 (JAK3-Y841), the binding forces between the kinase domain and ATP or ADP were similar. After phosphorylation of Y841, JAK3-pY841 exhibited more salt bridges and hydrogen bonds between ATP and the kinase than between ADP and the kinase. Consequently, the electrostatic binding force between ATP and the kinase was higher than that between ADP and the kinase. The result was that compared to ADP, ATP was more attractive to JAK3 when Y841 was phosphorylated. Therefore, JAK3-pY841 tended to bind ATP rather than ADP. This work provides new insights into the role of phosphorylation in kinase activation and ATP hydrolysis and sheds light on the importance of understanding the molecular mechanisms that regulate the kinase function.

Foix-Alajouanine Syndrome: A Case Report.

Foix-Alajouanine syndrome is a rare form of presentation of an arteriovenous malformation of the spinal cord that causes myelopathy in the thoracic and lumbar medullary segments. We present the case of a 46-year-old female who suffered from weakness in the lower limbs with sensation loss, low back pain, urinary incontinence, and constipation. The magnetic resonance image T2 sequence of the thoracic spine from T6 to T11 revealed abnormally hypointense signals in the posterior epidural region caused by larger arteries. A spinal digital subtraction angiography was useful to diagnose a right perimedullary fistula with venous drainage, which was satisfactorily embolized. The key to suspecting this diagnosis is the presence of dilated vessels in the posterior epidural space, which are evident in T2 and short tau inversion recovery (STIR)-weighted sequences. Physicians often misdiagnose Foix-Alajouanine syndrome, resulting in potential delays in care. Neurosurgeons can use surgery or endovascular embolization to treat this condition.