High-resolution phase-shifting Ronchi test.

A method adding phase-shifting capacity in two mutually perpendicular axes to the Ronchi test is presented in this work. The phase of the object with the position of the reflected ray on the grating was identified and used to solve the equation of reflection in two orthogonal directions. In this manner, the test-surface figure was obtained. The procedure was demonstrated with an inverse qualitative test and a direct, quantitative test. Both tests give results comparable to Fizeau interferometry, with the precision of the order of 25 nm peak to valley. This technique is a good alternative to interferometry because, in addition to its inherent high-resolution, it is possible to obtain the radius of curvature and conic constant, which interferometers, requiring auxiliary optics, cannot provide. This method also has a high dynamic range and is not as susceptible to vibrations or turbulence. The setup can be built with low-cost, readily available components, is easily aligned, uses a white light source, and can be made very lightweight and compact, which makes it ideal for mounting onto existing polishing machines in any optical fabrication workshop, to perform in situ surface metrology.

Academic excellence in Latin America: Social accountability of medical schools.

Context: Social accountability of medical schools has emerged as a standard of excellence in medical education during the last decade. However, the lack of valid and reliable instruments to estimate social accountability has limited the possibility of measuring the impact that medical schools have in society. Our aim was to develop an instrument and validate its use for assessing social accountability in Latin American countries.Methods: We used a three-phase mixed methods research design to develop, validate and estimate social accountability in a diverse convenient sample of 49 medical schools from 16 Latin American countries. We used a qualitative framework approach and a Delphi consensus method to design an instrument with high content validity. Finally, we assessed the psychometric properties of the instrument.Results: The Social Accountability Instrument for Latin America (SAIL) contained 21 items in four domains: mission and quality improvement, public policy, community engagement, and professional integrity. Its reliability index, estimated using Cronbach's alpha, was very high (0.96). Most of the medical schools that had ranked over the 80th percentile on traditional national academic estimates did not reach the 80th percentile using SAIL.Conclusions: There are validity arguments (content and reliability) to support the measurement of social accountability using the SAIL instrument. Its application showed that it provides a complementary dimension to that traditionally obtained when estimating quality in medical schools.

[Transional syndrome: from West to Lennox-Gastaut syndromes]. / Síndrome transicional: del síndrome de West al síndrome de Lennox-Gastaut.

West syndrome or infantile spasms is an epileptic encephalopathy, classified as generalized epilepsies and syndromes. There are multiple reports of the evolution from West to Lennox-Gastaut syndrome of 25 up to 60%, without a specific cause is determined. It has been reported that they may be only an epileptic entity age dependent that it would be in relation to the degree of brain immaturity. In this retrospective review of 130 cases of West syndrome, only 14 (10.7%) evolved to Lennox-Gastaut. Having received in all cases vigabatrin as a treatment, makes us suppose that the low incidence could be related to the use of this drug. Given that vigabatrin has a gabaergic action and increased levels of ACTH, may explain this relationship but this must be confirmed with the best knowledge of the intimate mechanisms of these serious epileptic encephalopathies.

Adjustment of a rapid method for quantification of Fusarium spp. spore suspensions in plant pathology.

The use of a Neubauer chamber is a broadly employed method when cell suspensions need to be quantified. However, this technique may take a long time and needs trained personnel. Spectrophotometry has proved to be a rapid, simple and accurate method to estimate the concentration of spore suspensions of isolates of the genus Fusarium. In this work we present a linear formula to relate absorbance measurements at 530nm with the number of microconidia/ml in a suspension.

[Status epilepticus in childhood]. / Estado de mal epiléptico en pediatría.

Status epilepticus is a medical emergency which presents seizures by 30 minutes or more of continuous activity, or two or more consecutive crises without full recovery of consciousness between them. Currently, it is considered that a seizure convulsive or not, that last more than 5 minutes should be considered a status epilepticus. Different drugs for the treatment of this disease have been used. There is a general consensus in an aggressive handling should be done to reduce their morbidity and mortality, without forgetting that the cause of status is important for its management, control, and its aftermath.

Untargeted analysis in post-COVID-19 patients reveals dysregulated lipid pathways two years after recovery.

Introduction: Similar to what it has been reported with preceding viral epidemics (such as MERS, SARS, or influenza), SARS-CoV-2 infection is also affecting the human immunometabolism with long-term consequences. Even with underreporting, an accumulated of almost 650 million people have been infected and 620 million recovered since the start of the pandemic; therefore, the impact of these long-term consequences in the world population could be significant. Recently, the World Health Organization recognized the post-COVID syndrome as a new entity, and guidelines are being established to manage and treat this new condition. However, there is still uncertainty about the molecular mechanisms behind the large number of symptoms reported worldwide. Aims and Methods: In this study we aimed to evaluate the clinical and lipidomic profiles (using non-targeted lipidomics) of recovered patients who had a mild and severe COVID-19 infection (acute phase, first epidemic wave); the assessment was made two years after the initial infection. Results: Fatigue (59%) and musculoskeletal (50%) symptoms as the most relevant and persistent. Functional analyses revealed that sterols, bile acids, isoprenoids, and fatty esters were the predicted metabolic pathways affected in both COVID-19 and post-COVID-19 patients. Principal Component Analysis showed differences between study groups. Several species of phosphatidylcholines and sphingomyelins were identified and expressed in higher levels in post-COVID-19 patients compared to controls. The paired analysis (comparing patients with an active infection and 2 years after recovery) show 170 dysregulated features. The relationship of such metabolic dysregulations with the clinical symptoms, point to the importance of developing diagnostic and therapeuthic markers based on cell signaling pathways.

Identification based on morphological and molecular characters of Phassus huebneri (Geyer) (Lepidoptera: Hepialidae), a ghost moth feeding on blackberry in Michoacán, Mexico: its biology and parasitoids.

Larvae of an unidentified Lepidopteran hepialid were found boring stems and crown roots of blackberry (Rubus sp.) in Michoacán, Mexico. In this study, the morphological and molecular identification of larvae and adults of this insect was performed. Preliminary aspects of biology, including information on parasitoids associated to larval stage, are also recorded. A total of 109 larvae of various instars were collected and three were reared to adult. The two females and one male were identified as Phassus huebneri (Geyer) (Lepidoptera: Hepialidae) following morphological characters. This identification was corroborated by comparing the cytochrome oxidase I (COI) barcode of two field-collected larvae (IIAFL1 and IIAFL2) with sequences of Phassus spp. obtained from GenBank. A Neighbor-Joining similarity analysis yielded a phenogram with two subclades. The first subclade grouped the IIAFL1 and IIAFL2 sequences with two other Mexican sequences categorized as P. huebneri, whereas in the second subclade other species belonging to the genus Phassus from Guatemala and Costa Rica were grouped together. Larval development of nine instars took about 14 months. Larvae reached a maximum length of 10 cm. The pupal stage lasted 39-41 days. Each of the two females laid over 1,000 unfertilized eggs within a period of 48 h. Larvae were parasitized by Dinera grisescens Fallen (Diptera: Tachinidae) and another unidentified Dinera sp. This study provides additional evidences on the distribution pattern of P. huebneri in western Mexico and presents the first record of this species feeding on one of the most economically important crops in Mexico.

Transfer to the clinic: refining forward programming of hPSCs to megakaryocytes for platelet production in bioreactors.

The production of in vitro-derived platelets has great potential for transfusion medicine. Here, we build on our experience in the forward programming (FoP) of human pluripotent stem cells (hPSCs) to megakaryocytes (MKs) and address several aspects of the complex challenges to bring this technology to the bedside. We first identify clinical-grade hPSC lines that generate MKs efficiently. We design a bespoke media to maximize both production and maturity of MKs and improve platelet output. Crucially, we transition the lentiviral-based FoP of hPSCs to a nonviral inducible system. We also show how small molecules promote a definitive hematopoiesis phenotype during the differentiation process, thereby increasing the quality of the final product. Finally, we generate platelets using a bioreactor designed to reproduce the physical cues that promote platelet production in the bone marrow. We show that these platelets are able to contribute to both thrombus formation in vitro and have a hemostatic effect in thrombocytopenic mice in vivo.

Engineering PEG-based hydrogels to foster efficient endothelial network formation in free-swelling and confined microenvironments.

In vitro tissue engineered models are poised to have significant impact on disease modeling and preclinical drug development. Reliable methods to induce microvascular networks in such microphysiological systems are needed to improve the size and physiological function of these models. By systematically engineering several physical and biomolecular properties of the cellular microenvironment (including crosslinking density, polymer density, adhesion ligand concentration, and degradability), we establish design principles that describe how synthetic matrix properties influence vascular morphogenesis in modular and tunable hydrogels based on commercial 8-arm poly (ethylene glycol) (PEG8a) macromers. We apply these design principles to generate endothelial networks that exhibit consistent morphology throughout depths of hydrogel greater than 1 mm. These PEG8a-based hydrogels have relatively high volumetric swelling ratios (>1.5), which limits their utility in confined environments such as microfluidic devices. To overcome this limitation, we mitigate swelling by incorporating a highly functional PEG-grafted alpha-helical poly (propargyl-l-glutamate) (PPLGgPEG) macromer along with the canonical 8-arm PEG8a macromer in gel formation. This hydrogel platform supports enhanced endothelial morphogenesis in neutral-swelling environments. Finally, we incorporate PEG8a-PPLGgPEG gels into microfluidic devices and demonstrate improved diffusion kinetics and microvascular network formation in situ compared to PEG8a-based gels.

[Pediatric neurocysticercosis]. / Neurocisticercosis en pediatría.

Cysticercosis: parasitic disease which affects 3% of the population in Mexico. It is considered that there are more than 50 million infected people in the world, endemic in Mexico, Central and South America, Africa, Asia and India. It is considered the most important neurological infectious disease world-wide for its clinical manifestations. The causal agent in pigs and humans is the cysticercus of the Taenia solium, that can lodge in muscle, brain and ventricles. If pork meat contaminated with cysticercus is eaten, the tapeworm will live in the human intestine and create thousands of eggs that are excreted by the feces. When food contaminated with fecal matter is consumed by man or pig, the cisticercosis is disseminated in several parts of the organism, specially CNS. Man is the only host of the tapeworm and the pig is the only intermediary, reason why the prevalence of the teniasis-cisticercosis depends on this bond. It is diagnosed in endemic zones by the presence of convulsion crises, focal migraine, neurological symptoms, disorders of vision, endocraneal hypertension and CT scan with hypodense zones or cysts with a hyperdense ring. The antiparasitic treatment in children is controversial among pediatricians; it is suggested to use it only in the non calcified cystic phase and in cases associated with epilepsy. Few are the cases of hydrocephalic or intraventricular cysticercus that need surgical treatment.

[Demyelinizing diseases in children. Acute disseminated encephalomyelitis and multiple sclerosis]. / Enfermedades desmielinizantes en niños.Encefalomielitis diseminada aguda y esclerosis múltiple.

The two main demyelinating diseases in children are reviewed. Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS). For its physiopathological characteristics, probable etiologies, clinical manifestations, diagnosis, treatment, prognosis, evolution, as well as atypical alterations that complicate its diagnosis, the smaller the child is, more study is needed before reaching the diagnosis. The International Study Group of Multiple Pediatric Sclerosis, published the operating definitions for demyelinating diseases acquired from the central nervous system in children: the ADEM is monophasic, polysymptomatic and with encephalopathy. Its duration is up to 3 months, with fluctuating symptoms and magnetic resonance findings. MS is an isolated monofocal or polyfocal syndrome, without encephalopathy. Currently, two different and distinguishable diseases are considered from the onset of symptoms.

Se revisan dos de las principales enfermedades desmielinizantes en niños, la encefalomielitis aguda diseminada (EAD) y la esclerosis múltiple (EM). Por sus características fisiopatológicas, etiologías probables, manifestaciones clínicas, diagnóstico, tratamiento, pronóstico, evolución, así como alteraciones atípicas que complican su diagnóstico; cuanto más pequeño es el paciente se necesita estudiar más, antes de llegar al diagnóstico. El Grupo Internacional de Estudio de Esclerosis Múltiple Pediátrica publicó las definiciones operativas para enfermedades desmielinizantes adquiridas del sistema nervioso central: la EAD es monofásica, polisintomática y con encefalopatía. Su duración es de hasta 3 meses, con síntomas fluctuantes y hallazgos en resonancia magnética. La EM se define como síndrome aislado monofocal o polifocal, sin encefalopatía. Actualmente se consideran dos enfermedades diferentes y distinguibles desde el inicio de los síntomas.

Establishing quasi-steady state operations of microphysiological systems (MPS) using tissue-specific metabolic dependencies.

Microphysiological systems (MPS), consisting of tissue constructs, biomaterials, and culture media, aim to recapitulate relevant organ functions in vitro. MPS components are housed in fluidic hardware with operational protocols, such as periodic complete media replacement. Such batch-like operations provide relevant nutrients and remove waste products but also reset cell-secreted mediators (e.g. cytokines, hormones) and potentially limit exposure to drugs (and metabolites). While each component plays an essential role for tissue functionality, MPS-specific nutrient needs are not yet well-characterized nor utilized to operate MPSs at more physiologically-relevant conditions. MPS-specific nutrient needs for gut (immortalized cancer cells), liver (human primary hepatocytes) and cardiac (iPSC-derived cardiomyocytes) MPSs were experimentally quantified. In a long-term study of the gut MPS (10 days), this knowledge was used to design operational protocols to maintain glucose and lactate at desired levels. This quasi-steady state operation was experimentally validated by monitoring glucose and lactate as well as MPS functionality. In a theoretical study, nutrient needs of an integrated multi-MPS platform (gut, liver, cardiac MPSs) were computationally simulated to identify long-term quasi-steady state operations. This integrative experimental and computational approach demonstrates the utilization of quantitative multi-scale characterization of MPSs and incorporating MPS-specific information to establish more physiologically-relevant experimental operations.

Interconnected Microphysiological Systems for Quantitative Biology and Pharmacology Studies.

Microphysiological systems (MPSs) are in vitro models that capture facets of in vivo organ function through use of specialized culture microenvironments, including 3D matrices and microperfusion. Here, we report an approach to co-culture multiple different MPSs linked together physiologically on re-useable, open-system microfluidic platforms that are compatible with the quantitative study of a range of compounds, including lipophilic drugs. We describe three different platform designs - "4-way", "7-way", and "10-way" - each accommodating a mixing chamber and up to 4, 7, or 10 MPSs. Platforms accommodate multiple different MPS flow configurations, each with internal re-circulation to enhance molecular exchange, and feature on-board pneumatically-driven pumps with independently programmable flow rates to provide precise control over both intra- and inter-MPS flow partitioning and drug distribution. We first developed a 4-MPS system, showing accurate prediction of secreted liver protein distribution and 2-week maintenance of phenotypic markers. We then developed 7-MPS and 10-MPS platforms, demonstrating reliable, robust operation and maintenance of MPS phenotypic function for 3 weeks (7-way) and 4 weeks (10-way) of continuous interaction, as well as PK analysis of diclofenac metabolism. This study illustrates several generalizable design and operational principles for implementing multi-MPS "physiome-on-a-chip" approaches in drug discovery.

[Cerebral palsy]. / Parálisis cerebral.

The term cerebral palsy (CP), is used for a great number of clinical neurological syndromes. The syndromes are characterized by having a common cause, motor defects. It is important, because they can cause a brain damage by presenting motor defects and some associated deficiencies, such as mental deficiency, epilepsy, language and visual defects and pseudobulbar paralysis, with the non-evolving fact. Some authors prefer using terms such as "non-evolving encephalopathies". In the treatment the utility of prevention programs of early stimulation and special rehabilitation methods, and treatment of associated deficiencies such as epilepsy, mental deficiency, language, audition and visual problems, and the attention deficit improve the prognosis in an important way. The prognosis depends on the severity of the disease and the associated manifestations.

Xanthogranulomatous Prostatitis, a Rare Prostatic Entity.

There are several benign prostatic pathologies that can clinically mimic a prostate adenocarcinoma. Xanthogranulomatous prostatitis is a benign inflammatory condition of the prostate and a rare entity. A 47-year old male, with 3 years of lower urinary tract symptoms, with a palpable hypogastric tumor, digital rectal examination: solid prostate, of approximately 60 g. Initial PSA was 0.90 ng/mL. He underwent surgical excision of the lower abdominal nodule and prostatectomy. Histopathology showed xanthogranulomatous prostatitis, without malignancy. Xanthogranulomatous prostatitis is an extremely rare entity that can simulate prostate adenocarcinoma, therefore having a correct histopathological diagnosis is essential.

On-demand dissolution of modular, synthetic extracellular matrix reveals local epithelial-stromal communication networks.

Methods to parse paracrine epithelial-stromal communication networks are a vital need in drug development, as disruption of these networks underlies diseases ranging from cancer to endometriosis. Here, we describe a modular, synthetic, and dissolvable extracellular matrix (MSD-ECM) hydrogel that fosters functional 3D epithelial-stromal co-culture, and that can be dissolved on-demand to recover cells and paracrine signaling proteins intact for subsequent analysis. Specifically, synthetic polymer hydrogels, modified with cell-interacting adhesion motifs and crosslinked with peptides that include a substrate for cell-mediated proteolytic remodeling, can be rapidly dissolved by an engineered version of the microbial transpeptidase Sortase A (SrtA) if the crosslinking peptide includes a SrtA substrate motif and a soluble second substrate. SrtA-mediated dissolution affected only 1 of 31 cytokines and growth factors assayed, whereas standard protease degradation methods destroyed about half of these same molecules. Using co-encapsulated endometrial epithelial and stromal cells as one model system, we show that the dynamic cytokine and growth factor response of co-cultures to an inflammatory cue is richer and more nuanced when measured from SrtA-dissolved gel microenvironments than from the culture supernate. This system employs accessible, reproducible reagents and facile protocols; hence, has potential as a tool in identifying and validating therapeutic targets in complex diseases.

Manejo de la vía aérea mediante intubación submental en fracturas maxilofaciales / Airway management by submental intubation in maxillofacial fractures

La intubación submentoniana es útil en procedimientos quirúrgicos en donde la intubación nasotraqueal está contraindicada y la intubación orotraqueal no es ideal debido a la fijación intermaxilar. Este informe describe dos pacientes masculinos que se presentaron al Hospital Nacional Rosales, en el servicio de Cirugía Maxilofacial de El Salvador, con historia de sufrir accidente de tránsito. El primer caso evidenció al examen radiológico fractura simple y desplazada de sínfisis mandibular, fractura simple huesos propios nasales y desviación del tabique nasal. El segundo caso es un paciente con fractura de sínfisis y doble cóndilo mandibular que presentaba imposibilidad a la apertura bucal. A través de la técnica del cirujano maxilofacial Hernández Altemir (España), el tubo endotraqueal atraviesa una incisión extraoral en la región submentoniana del suelo de la boca, para poder practicar reducción abierta de fracturas faciales, logrando adecuada oclusión, con mínimos cuidados posoperatorios y con una cicatriz estética. Al terminar la cirugía, la posición del tubo endotraqueal regresa a su posición original y el paciente evoluciona satisfactoriamente

Submental intubation is useful in surgical procedures where nasotracheal intubation is contraindicated and orotracheal intubation is not ideal due to intermaxillary fixation. This report describes two male patients who presented to the Rosales National Hospital, in the Maxillofacial Surgery service of El Salvador, with a history of suffering a traffic accident. The first case showed a simple and displaced fracture of the mandibular symphysis, simple nasal bone fracture and deviation of the nasal septum on radiological examination. The second case is a patient with a symphysis fracture and a double mandibular condyle that presented an inability to open the mouth. Through the technique of the maxillofacial surgeon Hernández Altemir (Spain), the endotracheal tube passes through an extraoral incision in the submental region of the floor of the mouth, in order to perform open reduction of facial fractures, achieving adequate occlusion, with minimal postoperative care and with an aesthetic scar. At the end of the surgery, the position of the endotracheal tube returns to its original position and the patient evolves satisfactorily

Regeneración ósea fisiológica en ameloblastoma mandibular con manejo conservador, seguimiento de 8 años / Physiological bone regeneration in mandibular ameloblastoma with conservative management, 8-year follow-up

El ameloblastoma es un tumor de origen odontogénico, con un comportamiento altamente agresivo. Estos pueden ser sólidos o multiquístico, uniquístico, periférico o extraóseo y desmoplásico. Dentro de las alternativas de manejo, se pre!ere un tratamiento que garantice seguridad para el paciente, como la resección radical o en bloque. Cada vez se utiliza menos el tratamiento conservador debido a una alta tasa de recidiva. Se presenta un caso de paciente masculino de 13 años, que fue visto en el Hospital Nacional Rosales, en el servicio de cirugía maxilofacial de El Salvador, por una in"amación en la región posterior mandibular en el lado izquierdo de la cara. El examen intraoral reveló leve extrusión y movilidad grado 2 de pieza 36 y 37. Los análisis clínicos, radiográ!cos e histopatológicos con!rmaron el diagnóstico de ameloblastoma. Fue tratado de forma conservadora mediante curetaje, ostectomía periférica y marsupialización. Se tuvo buen resultado estético y funcional, con un adecuado proceso de cicatrización y regeneración ósea !siológica, sin la necesidad de materiales de injerto óseo. Después de un seguimiento de 8 años, no hubo evidencia de recurrencia. Esta decisión depende de la variante clínica, la extensión tumoral y el adecuado control postoperatorio del paciente

Ameloblastoma is a tumor of odontogenic origin and highly aggressive. Four clinical variants of ameloblastomas are known: solid or multicystic, unicystic, peripheral or extra- osseous and desmoplastic. Among the treatment alternatives, a treatment that ensures a high percentage of successful prognosis for the patient is preferred, being the most indicated, radical resection, or in bulk. Conservative treatment is less used due to its recurrence rate. A clinical case of a 13-year-old male patient is presented to the Rosales National Hospital, in the Maxillofacial Surgery service of El Salvador with an in"ammation in the posterior mandibular region on the left side of the face. Intraoral examination revealed mild extrusion and mobility grade 2 of parts 37 and 36. Clinical, radiographic and histopathological analyzes con!rmed the diagnosis of Ameloblastoma. It was treated conservatively by curettage, peripheral osteotomy and marsupialization. A good aesthetic and functional result was obtained, applying the conservative technique, with an adequate healing and physiological bone regeneration, without recourse to bone grafting materials. After an 8-year follow-up no evidence was found of tumor recurrence. The decision regarding the type of treatment to be applied, depends on the clinical variables, tumor extension and adequate postoperative monitoring and care of the patient

Human vascular tissue models formed from human induced pluripotent stem cell derived endothelial cells.

Here we describe a strategy to model blood vessel development using a well-defined induced pluripotent stem cell-derived endothelial cell type (iPSC-EC) cultured within engineered platforms that mimic the 3D microenvironment. The iPSC-ECs used here were first characterized by expression of endothelial markers and functional properties that included VEGF responsiveness, TNF-α-induced upregulation of cell adhesion molecules (MCAM/CD146; ICAM1/CD54), thrombin-dependent barrier function, shear stress-induced alignment, and 2D and 3D capillary-like network formation in Matrigel. The iPSC-ECs also formed 3D vascular networks in a variety of engineering contexts, yielded perfusable, interconnected lumen when co-cultured with primary human fibroblasts, and aligned with flow in microfluidics devices. iPSC-EC function during tubule network formation, barrier formation, and sprouting was consistent with that of primary ECs, and the results suggest a VEGF-independent mechanism for sprouting, which is relevant to therapeutic anti-angiogenesis strategies. Our combined results demonstrate the feasibility of using a well-defined, stable source of iPSC-ECs to model blood vessel formation within a variety of contexts using standard in vitro formats.

Enfermedades desmielinizantes en niños: Encefalomielitis diseminada aguda y esclerosis múltiple / Demyelinizing diseases in children. Acute disseminated encephalomyelitis and multiple sclerosis

Se revisan dos de las principales enfermedades desmielinizantes en niños, la encefalomielitis aguda diseminada (EAD) y la esclerosis múltiple (EM). Por sus características fisiopatológicas, etiologías probables, manifestaciones clínicas, diagnóstico, tratamiento, pronóstico, evolución, así como alteraciones atípicas que complican su diagnóstico; cuanto más pequeño es el paciente se necesita estudiar más, antes de llegar al diagnóstico. El Grupo Internacional de Estudio de Esclerosis Múltiple Pediátrica publicó las definiciones operativas para enfermedades desmielinizantes adquiridas del sistema nervioso central: la EAD es monofásica, polisintomática y con encefalopatía. Su duración es de hasta 3 meses, con síntomas fluctuantes y hallazgos en resonancia magnética. La EM se define como síndrome aislado monofocal o polifocal, sin encefalopatía. Actualmente se consideran dos enfermedades diferentes y distinguibles desde el inicio de los síntomas.

The two main demyelinating diseases in children are reviewed. Acute disseminated encephalomyelitis (ADEM) and multiple sclerosis (MS). For its physiopathological characteristics, probable etiologies, clinical manifestations, diagnosis, treatment, prognosis, evolution, as well as atypical alterations that complicate its diagnosis, the smaller the child is, more study is needed before reaching the diagnosis. The International Study Group of Multiple Pediatric Sclerosis, published the operating definitions for demyelinating diseases acquired from the central nervous system in children: the ADEM is monophasic, polysymptomatic and with encephalopathy. Its duration is up to 3 months, with fluctuating symptoms and magnetic resonance findings. MS is an isolated monofocal or polyfocal syndrome, without encephalopathy. Currently, two different and distinguishable diseases are considered from the onset of symptoms.