Very rare arrangement of the pes anserinus: potential clinical significance.

The pes anserinus superficialis is composed of the semitendinosus, gracilis and sartorius tendons. Normally, they all insert to the medial side of the tibial tuberosity, and the first two are attached superiorly and medially to the tendon of the sartorius muscle. During anatomical dissection, a new pattern of arrangement of tendons creating the pes anserinus was found. The pes anserinus comprised three tendons; the semitendinosus tendon was located superiorly to the gracilis tendon, and they both had distal attachments on the medial side of the tibial tuberosity. This seemed like the normal type, but the tendon of the sartorius muscle created an additional superficial layer, its proximal part lying just below the gracilis tendon and covering the semitendinosus tendon and a small part of the gracilis tendon. After crossing the semitendinosus tendon it is attached to the crural fascia significantly below the tibial tuberosity. Good knowledge of the morphological variations of the pes anserinus superficialis is necessary during surgical procedures in the knee region, especially anterior ligament reconstruction.

An assessment of the variation of the intramuscular innervation of the gracilis muscle, with the aim of determining its neuromuscular compartments.

Some muscles present neuromuscular compartments, one of which is the gracilis muscle. The aim of the present study is to determine the number of compartments present within the gracilis muscle based on its intramuscular innervation patterns; such knowledge could be of value in free functional muscle transfer. The study comprised 72 gracilis muscles (38 women, 34 men), fixed in 10% formalin solution. The muscles were removed and then stained using Sihler's method. When sufficient transparency was achieved, some measurements were made. Three different types of intramuscular innervation were distinguished. Type I (70.8%) was featured by at least one direct proximal nerve branch. Type II (23.6%) presented at least one indirect proximal nerve branch. Type III (5.6%) did not possess any proximal nerve branch. The median of descended nerve branches was five. Considerable anatomical variation is possible within the intramuscular innervation of the gracilis muscle. The muscle presents neuromuscular compartments, but the exact number depends on the type of its intramuscular innervation and the number of the main descendent nerve branches. All three types seem to be appropriate for free functional muscle transfer. Our findings may be of great value for surgeons carrying out complex reconstructions with the use of the gracilis muscle.

Anatomic pattern of perforator arteries from proper digital arteries in human triphalangeal digits.

INTRODUCTION: The localization of the perforator artery for the performance of digital artery perforator (DAP) flaps poses a challenge. This study aims to describe the anatomical pattern of the perforator arteries originating from the proper digital artery in fresh cadaveric triphalangeal digits and to use this pattern as a point of reference for performing these flaps. MATERIAL AND METHOD: We performed a descriptive anatomical study on 28 fresh cadaveric hands (14 male, 14 female; 10 right hands, 18 left hands) after injecting the arterial system with latex. Digital photographs were taken of each specimen after dissection and the number of perforator arteries in each finger (second to fifth), phalanx (proximal, middle and distal) and finger side (radial or ulnar) were obtained by analysis in Adobe Photoshop CS6. RESULTS: We obtained statistically significant results when comparing the means of the number of perforator arteries between fingers, phalanx, finger side, gender and laterality. When analyzing the number of perforator arteries in each phalanx third in each finger, we found that more than 75% of specimens had at least one perforator artery in the two distal thirds of the proximal phalanx and the three-thirds of the middle phalanx and more than 50% had at least one in the proximal third of the distal phalanx. CONCLUSIONS: We present a homogeneous perforator artery anatomic pattern, by finger, phalanx, finger side, gender and laterality, consisting of a high density of perforator arteries in the distal proximal phalanx region, throughout the middle phalanx and in the proximal distal phalanx region, which would be the areas of greatest certainty to help predict the favorable evolution of a digital artery perforator flap in the fingers.

Humoral Response After SARS-CoV-2 Vaccination in Kidney Transplant Recipients: Role of Immunosuppression Therapy.

BACKGROUND: Messenger RNA vaccination against COVID-19 has been shown to produce an immune response with sufficient efficacy to prevent natural infection in immunocompetent recipients. However, the response in kidney transplant recipients is low. We aimed to evaluate the specific humoral response to SARS-CoV-2 after vaccination in a population of kidney transplant recipients and assess the main factors associated with a lack of response. METHODS: We undertook a prospective study of 105 kidney transplant recipients and 11 recipients of a combined kidney-pancreas transplant. We analyzed immunoglobulin G and immunoglobulin M antibodies after the patients received their second and third doses of the messenger RNA 1273 (Moderna) or BNT162b1 (BionTECH-Pfizer) vaccinations between February and November 2021. RESULTS: Mean (SD) age of the 116 patients was 50 (16) years, and 65% were men. They had their transplants for 40 months (IQR, 15-123 months), with 14% undergoing retransplant and 11% sensitized. The maintenance immunosuppression regimen was steroids + tacrolimus + mycophenolate (MMF) in 68% of the patients and any combination with mammalian target of rapamycin inhibitor (mTORi) in 28%. A humoral response developed in 40% of the patients 6 weeks (IQR, 4-10 weeks) after receiving the second dose of the vaccine. Of the 67 patients with no response to the second dose, 51 had an analysis of the humoral response after the third dose, which was positive in 16 (31%). A total of 80% received the Moderna vaccine and 20% the BionTECH-Pfizer. No patient experienced major adverse effects after the vaccination. Factors associated with a lack of humoral response to the vaccine were recipient age (odds ratio [OR], 1.02; 95% CI, 1.001-1.05; P = .04), diabetes (OR, 2.8; 95% CI, 1.2-6.9; P = .02), and treatment with MMF (OR, 2.6; 95% CI, 1.08-6.8; P = .03). Treatment with mTORi was associated with a better response to vaccination (OR, 0.3; 95% CI, 0.1-0.9; P = .04). CONCLUSIONS: The humoral response to the COVID-19 vaccine in kidney transplant recipients is poor. Factors related with this lack of immunity are recipient age and diabetes, plus MMF therapy, whereas mTORi therapy was associated with a better response to vaccination.

Carboplatin Plus Vincristine as an Alternative Chemotherapeutic Scheme in Patients With Glioblastoma.

Background and objective Alternative chemotherapy regimens, including cisplatin, carmustine, or other agents, have been shown to be effective; however, the use of carboplatin plus vincristine (C/V) has not been studied before. In this study, we aimed to determine the survival rates in patients treated with C/V, by comparing our findings with treatments based on temozolomide (TMZ), and to explore a possible relationship with the methylation status of the methylguanine methyltransferase (MGMT) promoter in patients with glioblastoma (GB). Methods A retrospective cohort study was conducted involving 45 surgically treated patients diagnosed with GB. Fresh tissue samples were examined by the DNA bisulfite conversion method to determine methylation status. After surgery, different chemotherapy regimens were employed as adjuvants. Follow-up of participants was performed as outpatients at three-month intervals to determine overall survival (OS), by comparing the use of TMZ versus C/V. Results MGMT promoter methylation status could only be determined in 35 samples; 20 patients received adjuvant chemotherapy, of which 14 were treated with C/V and six with TMZ-based schemes. The median OS (mOS) was eight months (range: 1-24 months). OS was 57.25% at six months, 48.7% at 12 months, and 28.5% at 24 months. In the TMZ group, an OS of 83% was observed at 24 months. In the C/V group, OS was 71.4% at six months, 57.1% at 12 months, and 35.7% at 24 months. Patients who did not receive adjuvant chemotherapy treatment had the lowest survival rates with an OS of 39.9% at six months, 26.6% at 12 months, and 19.9% ​​at 24 months. Conclusions Based on our findings, C/V offers an accessible and effective alternative treatment when the TMZ-based scheme is not accessible, providing higher rates of OS compared to patients without chemotherapy management. The methylation status of the MGMT promoter is a significant prognostic factor, resulting in higher survival rates among patients when it is methylated.

The hallucal interphalangeal ossicle: anatomy and basis for ultrasound-guided surgical shaving.

Painful lesions on the plantar aspect of the first interphalangeal joint (IPJ) of the hallux can be attributed to structures called ossicles, nodules, or sesamoids. The aims of the present study were first to verify that ultrasonography (US) is a high-sensitivity tool for diagnosing an interphalangeal ossicle (IO), and second to prove that US-guided-shaving surgery ("milling") is a safe and feasible technique for remodeling the IO. The study is divided into three parts. In the first part, the prevalence of IOs was estimated in 12 cadaver feet using US, anatomical dissection, and fluoroscopy. In the second, a detailed US and morphological description of the IO was obtained. In the third, six cadaver feet were subjected to surgical milling. IO prevalence was 41.6% in gross anatomy, 41.6% in US examination and just 16.6% in fluoroscopy. The ossicles had a mean length of 4 mm (± 2 mm) and a width of 7 mm (± 2 mm). The ossicles could be completely shaved in all specimens without injuring important anatomical structures. Our results indicate that US is a more precise tool for diagnosing an IO than X-ray. Moreover, our US-guided mini-invasive surgical technique appears feasible and safe.

Health Disparities, Inequities, and Social Determinants of Health in Multiple Sclerosis and Related Disorders in the US: A Review.

Importance: There is empirical evidence that social determinants of health (SDOH) impact health outcomes in Black and Hispanic and Latinx individuals in the US. Recently, SDOH have risen to the top as essential intervention targets that could help alleviate racial and ethnic disparities. Neuromyelitis optica spectrum disorder (NMOSD) disproportionately affects Black individuals, and multiple sclerosis (MS) has seen a recent shift in select racial groups. It is unclear to what degree SDOH have been investigated and contribute to racial and ethnic health disparities and inequities. Observations: This narrative review provides a contemporary synthesis of SDOH associated with racial and ethnic health disparities and inequities in MS, NMOSD, and other autoimmune disorders, such as myelin oligodendrocyte glycoprotein antibody (MOG-Ab)-associated disease. These immune-mediated neurological diseases were chosen for their capacity to be a high burden to society and because of complementary SDOH-associated challenges among minority populations. A paucity of research addressing inequities and the role of SDOH in MS and NMOSD was noted despite findings that Black individuals have a higher risk of developing MS or NMOSD and associated mortality compared with White individuals. Greater health disparities were also found for those with lower income and education, lower health literacy, and negative illness perceptions in MS. No studies in MOG-Ab disorders were found. Conclusions and Relevance: Increased efforts are needed to better understand the role of SDOH in racial and ethnic health disparities and inequities in MS, NMOSD, and emerging autoimmune disorders. This includes developing research frameworks aimed at understanding the magnitude and interrelationships of SDOH to better develop system-based multilevel interventions across the spectrum of care for these neurological conditions.

Anatomic mapping of the collateral branches of the external carotid artery with regard to daily clinical practice.

BACKGROUND: To identify the anatomical variations of the main branches of the external carotid artery (lingual, facial, occipital, ascending pharyngeal and sternocleidomastoid), giving information about the calibers and origins with the aim of creating a new classification useful in clinical practice. MATERIAL AND METHODS: 193 human embalmed body-donors were dissected. The data collected were analyzed using the Chi² test. The results of previous studies were reviewed. RESULTS: The majority of the anterior arterial branches (superior thyroid, facial and lingual artery) were observed with an independent origin, respectively, classified as pattern I (80.83%, 156/193). In 17.62% (34/193) a linguofacial trunk, pattern II, has been observed, only in 1,04% (2/193) a thyrolingual trunk, pattern III, has been found and in one case (1/193, 0.52%) one thyrolinguofacial trunk, pattern IV, was found. Depending on the posterior branches (occipital and ascending pharyngeal), four different types could be determined: type a, the posterior arteries originated independently, type b, the posterior arteries originated in a common trunk, type c, the ascending pharyngeal artery was absent, type d, the occipital artery was absent. CONCLUSION: Anatomical variations in these arteries are relevant in daily clinical practice due to growing applications, e.g., in Interventional Radiology techniques. Knowledge of these anatomical references could help clinicians in the interpretation of the carotid system.

Clinical Relevance of Corticosteroid Withdrawal on Graft Histological Lesions in Low-Immunological-Risk Kidney Transplant Patients.

The impact of corticosteroid withdrawal on medium-term graft histological changes in kidney transplant (KT) recipients under standard immunosuppression is uncertain. As part of an open-label, multicenter, prospective, phase IV, 24-month clinical trial (ClinicalTrials.gov, NCT02284464) in low-immunological-risk KT recipients, 105 patients were randomized, after a protocol-biopsy at 3 months, to corticosteroid continuation (CSC, n = 52) or corticosteroid withdrawal (CSW, n = 53). Both groups received tacrolimus and MMF and had another protocol-biopsy at 24 months. The acute rejection rate, including subclinical inflammation (SCI), was comparable between groups (21.2 vs. 24.5%). No patients developed dnDSA. Inflammatory and chronicity scores increased from 3 to 24 months in patients with, at baseline, no inflammation (NI) or SCI, regardless of treatment. CSW patients with SCI at 3 months had a significantly increased chronicity score at 24 months. HbA1c levels were lower in CSW patients (6.4 ± 1.2 vs. 5.7 ± 0.6%; p = 0.013) at 24 months, as was systolic blood pressure (134.2 ± 14.9 vs. 125.7 ± 15.3 mmHg; p = 0.016). Allograft function was comparable between groups and no patients died or lost their graft. An increase in chronicity scores at 2-years post-transplantation was observed in low-immunological-risk KT recipients with initial NI or SCI, but CSW may accelerate chronicity changes, especially in patients with early SCI. This strategy did, however, improve the cardiovascular profiles of patients.

Impact of HLA Mismatching on Early Subclinical Inflammation in Low-Immunological-Risk Kidney Transplant Recipients.

The impact of human leukocyte antigen (HLA)-mismatching on the early appearance of subclinical inflammation (SCI) in low-immunological-risk kidney transplant (KT) recipients is undetermined. We aimed to assess whether HLA-mismatching (A-B-C-DR-DQ) is a risk factor for early SCI. As part of a clinical trial (Clinicaltrials.gov, number NCT02284464), a total of 105 low-immunological-risk KT patients underwent a protocol biopsy on the third month post-KT. As a result, 54 presented SCI, showing a greater number of total HLA-mismatches (p = 0.008) and worse allograft function compared with the no inflammation group (48.5 ± 13.6 vs. 60 ± 23.4 mL/min; p = 0.003). Multiple logistic regression showed that the only risk factor associated with SCI was the total HLA-mismatch score (OR 1.32, 95%CI 1.06-1.64, p = 0.013) or class II HLA mismatching (OR 1.51; 95%CI 1.04-2.19, p = 0.032) after adjusting for confounder variables (recipient age, delayed graft function, transfusion prior KT, and tacrolimus levels). The ROC curve illustrated that the HLA mismatching of six antigens was the optimal value in terms of sensitivity and specificity for predicting the SCI. Finally, a significantly higher proportion of SCI was seen in patients with >6 vs. ≤6 HLA-mismatches (62.3 vs. 37.7%; p = 0.008). HLA compatibility is an independent risk factor associated with early SCI. Thus, transplant physicians should perhaps be more aware of HLA mismatching to reduce these early harmful lesions.

Socioeconomic status and access to multiple sclerosis treatment in Mexico.

INTRODUCTION: Multiple sclerosis (MS) is a chronic neurological autoimmune condition and the leading non-traumatic cause of neurological disability worldwide. Disease-modifying therapies (DMT) directly impact on the long-term prognosis of patients with MS preventing relapses and the associated disability progression. Here, we analyzed the impact of socioeconomic status (SES) on DMT access in Mexican patients. METHODS: We evaluated the association between SES and DMT access using the MS registry from the National Institute of Neurology and Neurosurgery in Mexico City. We included 974 patients with MS (McDonald 2010 criteria). We categorized SES according to the 2018 Mexican Association of Market Research Agencies (AMAI) SES classification. We analyzed DMT type, MS phenotype, educational level, symptomatic onset to diagnosis, EDSS at arrival, as well as the progression index. Chi-squared and Wilcoxon tests were used, and multivariable analysis performed for DMT access. RESULTS: When comparing the lower versus higher levels of SES, a significant association was found on the percentage of patients with higher levels of disability (EDSS >6) at arrival, the proportion of patients not receiving any DMT and a higher proportion of secondary progressive MS (p=0.006, p<0.001and p=0.004, respectively). We also found that lower educational levels had a significance and inverse association with EDSS on first visit (p=0.019), symptomatic onset to diagnosis (p<0.001) and a higher disability status at arrival (EDSS >6, p=0.010). CONCLUSIONS: Our study suggests that SES is an important factor determining not only prompt but overall access to highly effective DMT. Lower SES are associated with greater levels of disability at the first clinic visit and a higher proportion of patients not receiving DMT up to 12 months of follow-up.

Anatomical basis of a safe mini-invasive technique for lengthening of the anterior gastrocnemius aponeurosis.

BACKGROUND: The surgical procedure itself of lengthening the gastrocnemius muscle aponeurosis is performed to treat multiple musculoskeletal, neurological and metabolical pathologies related to a gastro-soleus unit contracture such as plantar fasciitis, Achilles tendinopathy, metatarsalgia, cerebral palsy, or diabetic foot ulcerations. Therefore, the aim of our research was to prove the effectiveness and safety of a new ultrasound-guided surgery-technique for the lengthening of the anterior gastrocnemius muscle aponeurosis, the "GIAR"- technique: the gastrocnemius-intramuscular aponeurosis release. METHODS AND RESULTS: An ultrasound-guided surgical GIAR on ten fresh-frozen specimens (10 donors, 8 male, 2 females, 5 left and 5 right) was performed. Exclusion criteria of the donated bodies to science were BMI above 35 (impaired ultrasound echogenicity), signs of traumas in the ankle and crural region, a history of ankle or foot ischemic vascular disorder, surgery or space-occupying mass lesions. The surgical procedures were performed by two podiatric surgeons with more than 6 years of experience in ultrasound-guided procedures. The anterior gastrocnemius muscle aponeurosis was entirely transected in 10 over 10 specimens, with a mean portal length of 2 mm (± 1 mm). The mean gain at the ankle joint ROM after the GIAR was 7.9° (± 1.1°). No damages of important anatomical structures could be found. CONCLUSION: Results of this study indicate that our novel ultrasound-guided surgery for the lengthening of the anterior gastrocnemius muscle aponeurosis (GIAR) might be an effective and safe procedure.

Anatomic basis for a new ultrasound-guided, mini-invasive technique for release of the deep transverse metatarsal ligament.

INTRODUCTION: Morton's neuroma is an entrapment neuropathy of the third common plantar digital nerve, caused by the deep transverse metatarsal ligament (DTML). Minimally invasive or percutaneous surgery is a very common procedure, but surgical effectivity of this technique remains controversial. The goal of our study was to prove the effectiveness and safety of a new ultrasound-guided technique for DTML-release in a cadaver model. MATERIALS, METHODS, AND RESULTS: The DTML was visualized in 10 fresh frozen donated body to science-feet (eight male and two females, five left and five right) using an US device (GE Logic R7; 13 MHz linear probe, Madrid, Spain). Consecutively, minimally invasive ultrasound-guided surgery was performed. Exclusion criteria of the donated bodies to science were previous history of forefoot surgery and space occupying mass lesions. The complete release of the ligament was achieved in all specimens without damage of any important anatomical structures as proven by anatomical dissection. CONCLUSIONS: The results of this study indicate that our novel approach of an ultrasound-guided release of the DTML is safer and more effective compared to blind techniques. The DTML could reliably be visualized and securely cut through a dorsal, minimally invasive surgical incision of only 2 mm.

Peripheral Vascular Disease and Kidney Transplant Outcomes: Rethinking an Important Ongoing Complication.

Peripheral vascular disease (PVD) is highly prevalent in patients on the waiting list for kidney transplantation (KT) and after transplantation and is associated with impaired transplant outcomes. Multiple traditional and nontraditional risk factors, as well as uremia- and transplant-related factors, affect 2 processes that can coexist, atherosclerosis and arteriosclerosis, leading to PVD. Some pathogenic mechanisms, such as inflammation-related endothelial dysfunction, mineral metabolism disorders, lipid alterations, or diabetic status, may contribute to the development and progression of PVD. Early detection of PVD before and after KT, better understanding of the mechanisms of vascular damage, and application of suitable therapeutic approaches could all minimize the impact of PVD on transplant outcomes. This review focuses on the following issues: (1) definition, epidemiological data, diagnosis, risk factors, and pathogenic mechanisms in KT candidates and recipients; (2) adverse clinical consequences and outcomes; and (3) classical and new therapeutic approaches.

Effect of rituximab on disease activity in latin American patients with anti-aquaporin-4 (+) neuromyelitis optica spectrum disorder.

OBJECTIVES: The aim of the present study is to explore the efficacy of rituximab in patients with Neuromyelitis Optica spectrum disorders (NMOsd) with positive AQP4-IgG serostatus. PATIENTS AND METHODS: In this single center retrospective study, we recruited seropositive anti-AQP4 NMOsd patients who received treatment with Rituximab (RTX) for at least 2 years. Demographics were described and annualized relapse rate (AAR) and survival analysis were performed for time to relapse with Rituximab. All p values ≤0.05 we considered statistically significant. RESULTS: A total of 15 patients (100 % female) were identified. Mean age of disease onset was 34 ±â€¯11 years, mean time of disease was 8.11 ±â€¯4.04 years and the median number of relapses was 5 (2-16). Ten patients received an immunosuppressive agent before RTX. Mean age of RTX initiation was 37 ±â€¯12 with a mean treatment duration of 52 ±â€¯28 months. The median ARR before and after treatment with RTX was 2.08 vs 0.00, respectively, with a difference of -2.08 (p < 0.001) CONCLUSIONS: This study shows a statistically significant reduction in the ARR and an increase in the relapse-free rate in AQP4-IgG NMOsd patients treated with RTX. These findings support the use of rituximab in our population, and indirectly suggests that its prompt use could modify the course of the disease.

Recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (Covid-19) en pacientes con trasplante renal / Recommendations on management of the SARS-CoV-2 coronavirus pandemic (Covid-19) in kidney transplant patients

La pandemia por coronavirus SARS-CoV-2 (Covid-19) está evolucionando de manera muy rápida y representa un riesgo especial en pacientes inmunodeprimidos y con comorbilidades añadidas. El conocimiento sobre esta infección emergente va también en aumento, si bien, aún sigue habiendo muchas incógnitas, sobre todo en la población con trasplante renal. Este manuscrito presenta una propuesta de actuación con recomendaciones generales y específicas para proteger y prevenir de la infección a esta población tan vulnerable como son los receptores de un trasplante renal

The SARS-CoV-2 (Covid-19) coronavirus pandemic is evolving very quickly and means a special risk for both immunosuppressed and comorbid patients. Knowledge about this growing infection is also increasing although many uncertainties remain, especially in the kidney transplant population. This manuscript presents a proposal for action with general and specific recommendations to protect and prevent infection in this vulnerable population such as kidney transplant recipients

[Recommendations on management of the SARS-CoV-2 coronavirus pandemic (Covid-19) in kidney transplant patients]. / Recomendaciones en el manejo de la pandemia por coronavirus SARS-CoV-2 (Covid-19) en pacientes con trasplante renal.

The SARS-CoV-2 (Covid-19) coronavirus pandemic is evolving very quickly and means a special risk for both immunosuppressed and comorbid patients. Knowledge about this growing infection is also increasing although many uncertainties remain, especially in the kidney transplant population. This manuscript presents a proposal for action with general and specific recommendations to protect and prevent infection in this vulnerable population such as kidney transplant recipients.

Waiting List and Kidney Transplant Vascular Risk: An Ongoing Unmet Concern.

BACKGROUND: Chronic kidney disease (CKD) is an important independent risk factor for adverse cardiovascular events in patients waitlisted for kidney transplantation (KT). Although KT reduces cardiovascular risk, these patients still have a higher all-cause and cardiovascular mortality than the general population. This concerning situation is due to a high burden of traditional and nontraditional risk factors as well as uremia-related factors and transplant-specific factors, leading to 2 differentiated processes under the framework of CKD, atherosclerosis and arteriosclerosis. These can be initiated by insults to the vascular endothelial endothelium, leading to vascular calcification (VC) of the tunica media or the tunica intima, which may coexist. Several pathogenic mechanisms such as inflammation-related endothelial dysfunction, mineral metabolism disorders, activation of the renin-angiotensin system, reduction of nitric oxide, lipid disorders, and the fibroblast growth factor 23-klotho axis are involved in the pathogenesis of atherosclerosis and arteriosclerosis, including VC. SUMMARY: This review focuses on the current understanding of atherosclerosis and arteriosclerosis, both in patients on the waiting list as well as in kidney transplant recipients, emphasizing the cardiovascular risk factors in both populations and the inflammation-related pathogenic mechanisms. Key Message: The importance of cardiovascular risk factors and the pathogenic mechanisms related to inflammation in patients waitlisted for KT and kidney transplant recipients.

Air Pollution, Multiple Sclerosis and its Relevance to Mexico City.

Long-term exposure to air pollution has been linked with the development of neurodegenerative diseases. The proposed mechanisms include neuroinflammation and brain oxidative stress. Multiple sclerosis (MS) is a neurodegenerative disease with an auto-immune physiopathology and some studies have associated it with long-term exposure to airborne particulate matter. In this opinion we discuss the current body of knowledge regarding air pollution and the risk of MS as well as MS relapses. Also, its relevance in the case of Mexico City is discussed.