[Perception of the educational environment in residents of medical specialties in Chilean universities]. / Percepción del ambiente educacional de postgrado en residentes de especialidades médicas de universidades chilenas.

BACKGROUND: The Learning Environment (LE) influences the performance of students, learning, social life, mental health, and the future of work. AIM: To assess the learning environment (LE) among medical residents of 64 specialties. MATERIAL AND METHODS: Two validated instruments "Postgraduate Hospital Education Environment Measure" (PHEEM) and "Ambulatory Care Learning Educational Environment" (ACLEEM), and open questions were answered online by 1259 residents from 15 universities. A descriptive and analytical statistical analysis and semantic deductive-inductive analyses of open questions were performed. RESULTS: LE was positive rather than negative (PHEEM of 100.5 points (79-116) and ACLEEM of 138.5 points (120-157)). An age over 32 years, male sex, studying in a private university, being in first year of residence and being in a non-surgical specialty were associated with a better PHEEM score (p < 0.05). For ACLEEM, the first year of specialty, a non-surgical specialty and studying in a private university were associated with better scores (p < 0.05). Two programs had excellent LE (Pathological Anatomy and Ophthalmology) and no specialty had a very poor performance or many problems. Aspects of teaching, clinical activities, and teachers were strengths reported by students. Aspects to improve were teaching, protected times and clinical activities. CONCLUSIONS: LE among medical specialties had more positive than negative features, but with areas that should be improved.

Genetic Profile of Patients with Limb-Girdle Muscle Weakness in the Chilean Population.

Hereditary myopathies are a group of genetically determined muscle disorders comprising more than 300 entities. In Chile, there are no specific registries of the distinct forms of these myopathies. We now report the genetic findings of a series of Chilean patients presenting with limb-girdle muscle weakness of unknown etiology. Eighty-two patients were explored using high-throughput sequencing approaches with neuromuscular gene panels, establishing a definite genetic diagnosis in 49 patients (59.8%) and a highly probable genetic diagnosis in eight additional cases (9.8%). The most frequent causative genes identified were DYSF and CAPN3, accounting for 22% and 8.5% of the cases, respectively, followed by DMD (4.9%) and RYR1 (4.9%). The remaining 17 causative genes were present in one or two cases only. Twelve novel variants were identified. Five patients (6.1%) carried a variant of uncertain significance in genes partially matching the clinical phenotype. Twenty patients (24.4%) did not carry a pathogenic or likely pathogenic variant in the phenotypically related genes, including five patients (6.1%) presenting an autoimmune neuromuscular disorder. The relative frequency of the different forms of myopathy in Chile is like that of other series reported from different regions of the world with perhaps a relatively higher incidence of dysferlinopathy.

Percepción del ambiente educacional de postgrado en residentes de especialidades médicas de universidades chilenas / Perception of the educational environment in residents of medical specialties in Chilean universities

BACKGROUND: The Learning Environment (LE) influences the performance of students, learning, social life, mental health, and the future of work. Aim: To assess the learning environment (LE) among medical residents of 64 specialties. MATERIAL AND METHODS: Two validated instruments "Postgraduate Hospital Education Environment Measure" (PHEEM) and "Ambulatory Care Learning Educational Environment" (ACLEEM), and open questions were answered online by 1259 residents from 15 universities. A descriptive and analytical statistical analysis and semantic deductive-inductive analyses of open questions were performed. Results: LE was positive rather than negative (PHEEM of 100.5 points (79-116) and ACLEEM of 138.5 points (120-157)). An age over 32 years, male sex, studying in a private university, being in first year of residence and being in a non-surgical specialty were associated with a better PHEEM score (p < 0.05). For ACLEEM, the first year of specialty, a non-surgical specialty and studying in a private university were associated with better scores (p < 0.05). Two programs had excellent LE (Pathological Anatomy and Ophthalmology) and no specialty had a very poor performance or many problems. Aspects of teaching, clinical activities, and teachers were strengths reported by students. Aspects to improve were teaching, protected times and clinical activities. CONCLUSIONS: LE among medical specialties had more positive than negative features, but with areas that should be improved.

International retrospective natural history study of LMNA-related congenital muscular dystrophy.

Muscular dystrophies due to heterozygous pathogenic variants in LMNA gene cover a broad spectrum of clinical presentations and severity with an age of onset ranging from the neonatal period to adulthood. The natural history of these conditions is not well defined, particularly in patients with congenital or early onset who arguably present with the highest disease burden. Thus the definition of natural history endpoints along with clinically revelant outcome measures is essential to establishing both clinical care planning and clinical trial readiness for this patient group. We designed a large international cross-sectional retrospective natural history study of patients with genetically proven muscle laminopathy who presented with symptoms before two years of age intending to identify and characterize an optimal clinical trial cohort with pertinent motor, cardiac and respiratory endpoints. Quantitative statistics were used to evaluate associations between LMNA variants and distinct clinical events. The study included 151 patients (median age at symptom onset 0.9 years, range: 0.0-2.0). Age of onset and age of death were significantly lower in patients who never acquired independent ambulation compared to patients who achieved independent ambulation. Most of the patients acquired independent ambulation (n = 101, 66.9%), and subsequently lost this ability (n = 86; 85%). The age of ambulation acquisition (median: 1.2 years, range: 0.8-4.0) and age of ambulation loss (median: 7 years, range: 1.2-38.0) were significantly associated with the age of the first respiratory interventions and the first cardiac symptoms. Respiratory and gastrointestinal interventions occurred during first decade while cardiac interventions occurred later. Genotype-phenotype analysis showed that the most common mutation, p.Arg249Trp (20%), was significantly associated with a more severe disease course. This retrospective natural history study of early onset LMNA-related muscular dystrophy confirms the progressive nature of the disorder, initially involving motor symptoms prior to onset of other symptoms (respiratory, orthopaedic, cardiac and gastrointestinal). The study also identifies subgroups of patients with a range of long-term outcomes. Ambulatory status was an important mean of stratification along with the presence or absence of the p.Arg249Trp mutation. These categorizations will be important for future clinical trial cohorts. Finally, this study furthers our understanding of the progression of early onset LMNA-related muscular dystrophy and provides important insights into the anticipatory care needs of LMNA-related respiratory and cardiac manifestations.

Deoxynucleoside Therapy for Thymidine Kinase 2-Deficient Myopathy.

OBJECTIVE: Thymidine kinase 2, encoded by the nuclear gene TK2, is required for mitochondrial DNA maintenance. Autosomal recessive TK2 mutations cause depletion and multiple deletions of mtDNA that manifest predominantly as a myopathy usually beginning in childhood and progressing relentlessly. We investigated the safety and efficacy of deoxynucleoside monophosphate and deoxynucleoside therapies. METHODS: We administered deoxynucleoside monophosphates and deoxynucleoside to 16 TK2-deficient patients under a compassionate use program. RESULTS: In 5 patients with early onset and severe disease, survival and motor functions were better than historically untreated patients. In 11 childhood and adult onset patients, clinical measures stabilized or improved. Three of 8 patients who were nonambulatory at baseline gained the ability to walk on therapy; 4 of 5 patients who required enteric nutrition were able to discontinue feeding tube use; and 1 of 9 patients who required mechanical ventilation became able to breathe independently. In motor functional scales, improvements were observed in the 6-minute walk test performance in 7 of 8 subjects, Egen Klassifikation in 2 of 3, and North Star Ambulatory Assessment in all 5 tested. Baseline elevated serum growth differentiation factor 15 levels decreased with treatment in all 7 patients tested. A side effect observed in 8 of the 16 patients was dose-dependent diarrhea, which did not require withdrawal of treatment. Among 12 other TK2 patients treated with deoxynucleoside, 2 adults developed elevated liver enzymes that normalized following discontinuation of therapy. INTERPRETATION: This open-label study indicates favorable side effect profiles and clinical efficacy of deoxynucleoside monophosphate and deoxynucleoside therapies for TK2 deficiency. ANN NEUROL 2019;86:293-303.

Retrospective natural history of thymidine kinase 2 deficiency.

BACKGROUND: Thymine kinase 2 (TK2) is a mitochondrial matrix protein encoded in nuclear DNA and phosphorylates the pyrimidine nucleosides: thymidine and deoxycytidine. Autosomal recessive TK2 mutations cause a spectrum of disease from infantile onset to adult onset manifesting primarily as myopathy. OBJECTIVE: To perform a retrospective natural history study of a large cohort of patients with TK2 deficiency. METHODS: The study was conducted by 42 investigators across 31 academic medical centres. RESULTS: We identified 92 patients with genetically confirmed diagnoses of TK2 deficiency: 67 from literature review and 25 unreported cases. Based on clinical and molecular genetics findings, we recognised three phenotypes with divergent survival: (1) infantile-onset myopathy (42.4%) with severe mitochondrial DNA (mtDNA) depletion, frequent neurological involvement and rapid progression to early mortality (median post-onset survival (POS) 1.00, CI 0.58 to 2.33 years); (2) childhood-onset myopathy (40.2%) with mtDNA depletion, moderate-to-severe progression of generalised weakness and median POS at least 13 years; and (3) late-onset myopathy (17.4%) with mild limb weakness at onset and slow progression to respiratory insufficiency with median POS of 23 years. Ophthalmoparesis and facial weakness are frequent in adults. Muscle biopsies show multiple mtDNA deletions often with mtDNA depletion. CONCLUSIONS: In TK2 deficiency, age at onset, rate of weakness progression and POS are important variables that define three clinical subtypes. Nervous system involvement often complicates the clinical course of the infantile-onset form while extraocular muscle and facial involvement are characteristic of the late-onset form. Our observations provide essential information for planning future clinical trials in this disorder.

Novel splice-affecting variants in CYP27A1 gene in two Chilean patients with Cerebrotendinous Xanthomatosis.

Cerebrotendinous Xanthomatosis (CTX), a rare lipid storage disorder, is caused by recessive loss-of-function mutations of the 27-sterol hydroxylase (CYP27A1), producing an alteration of the synthesis of bile acids, with an accumulation of cholestanol. Clinical characteristics include juvenile cataracts, diarrhea, tendon xanthomas, cognitive impairment and other neurological manifestations. Early diagnosis is critical, because treatment with chenodeoxycholic acid may prevent neurological damage. We studied the CYP27A1 gene in two Chilean CTX patients by sequencing its nine exons, exon-intron boundaries, and cDNA from peripheral blood mononuclear cells. Patient 1 is a compound heterozygote for the novel substitution c.256-1G > T that causes exon 2 skipping, leading to a premature stop codon in exon 3, and for the previously-known pathogenic mutation c.1183C > T (p.Arg395Cys). Patient 2 is homozygous for the novel mutation c.1185-1G > A that causes exon 7 skipping and the generation of a premature stop codon in exon 8, leading to the loss of the crucial adrenoxin binding domain of CYP27A1.

A prospective cohort study of the prevalence of growth, facial, and central nervous system abnormalities in children with heavy prenatal alcohol exposure.

BACKGROUND: Most children who are exposed to large quantities of alcohol in utero do not develop fetal alcohol syndrome (FAS). Population-based prospective data on the risk of developing components of fetal alcohol spectrum disorders (FASD), however, are limited. METHODS: This was a prospective cohort study of 9,628 women screened during their first prenatal appointment in Chile, which identified 101 who consumed at least 4 drinks/d (exposed) matched with 101 women with no reported alcohol consumption during pregnancy (unexposed). Detailed alcohol consumption data were collected during the pregnancy. Children were evaluated up to 8.5 years of age by clinicians masked to exposure status. RESULTS: One or more functional central nervous system abnormalities were present in 44.0% (22/50) of the exposed children compared to 13.6% (6/44) of the unexposed (p = 0.002). Growth restriction was present in 27.2% (25/92) of the exposed and 12.5% (12/96) of the unexposed (p = 0.02). Abnormal facial features were present in 17.3% (14/81) of the exposed children compared to 1.1% (1/89) of the unexposed children (p = 0.0002) by direct examination. Of the 59 exposed children with data available to detect at least 1 abnormality, 12 (20.3%) had no abnormalities. Binge drinking from conception to recognition of pregnancy (OR = 1.48 per day, 95% CI: 1.15 to 1.91, p = 0.002) and after recognition of pregnancy (OR= 1.41 per day, 95% CI: 1.01 to 1.95, p = 0.04) and total number of drinks consumed per week from conception to recognition of pregnancy (OR = 1.02 per drink, 95% CI: 1.01 to 1.04, p = 0.0009) were significantly associated with abnormal child outcome. CONCLUSIONS: After exposure to heavy alcohol consumption during pregnancy, 80% of children had 1 or more abnormalities associated with alcohol exposure. Patterns of alcohol use that posed the greatest risk of adverse outcomes were binge drinking and high total weekly intake. Functional neurologic impairment occurred most frequently and may be the only sign to alert physicians to prenatal alcohol exposure.

Aumento de transaminasas: una manifestación de distrofia muscular de Duchenne / Transaminases increase: a manifestation of Duchenne's muscular dystrophy

Commonly used in clinical practice, glutamic oxalacetic (GOT) and glutamic piruvic (GPT) transaminases are produced in various body tissues, including striated muscle, so their blood elevation is not due exclusively to liver disease. The objective of this study is to demonstrate the correlation between elevated creatinkinase (CK) and transaminases in patients with diagnosis of Duchenne muscular dystrophy (DMD), the most frequent neuromuscular disease in children. Patients and Method: Assessment in 61 children with diagnosis of DMD of CK, AST and ALT levels, and their correlation. Results: Aill patients had increase of CK ( = 13.363 IU/L), AST ( = 203 lU/L) and ALT ( = 194 IU/L) above normal values. The increase of transaminases related directly with the increase of CK. Conclusion: Patients with DMD have increased transaminases, so it is necessary to include this diagnostic possibility in a child with hypertransaminemia, prior to performing liver biopsy.

Las transaminasas que comúnmente se utilizan en clínica, glutámico oxalacética (GOT) y glutámico pirúvica (GPT) son producidas en varios tejidos del organismo entre los cuales se cuenta el músculo estriado, por lo que la elevación de transaminasas en sangre no es producida exclusivamente por enfermedades hepáticas. Objetivo: Demostrar la correlación entre el alza de la creatinkinasa (CK) y transaminasas en pacientes con el diagnóstico de distrofia muscular de Duchenne (DMD), la enfermedad neuromuscular más frecuente en niños. Pacientes y Método: Evaluación en 61 niños con diagnóstico de DMD de los niveles de CK, GOT y GPT y la relación entre ellos. Resultados: Todos los pacientes presentaron aumento de CK ( = 13.363 IU/L), GOT ( = 203 IU/L) y GPT ( = 194 IU/L) sobre los valores normales. El aumento de transaminasas se relacionó en forma directa con aumento de CK. Conclusiones: Los pacientes con DMD presentan transaminasas aumentadas, por lo que es necesario incluir esta posibilidad diagnóstica en niños con hipertransaminasemia, previo a realizar biopsia hepática.

Myotonic dystrophy in a female with myasthenia gravis.

The likelihood of coexistence in the same patient of myasthenia gravis and myotonic dystrophy has been estimated at 1 in 40 million. The case of a patient in whom both diagnoses were made is reported here. A 13-year-old girl was diagnosed with myasthenia gravis because of weakness, fluctuating fatigability, and mild difficulty with chewing and swallowing. She had ptosis, with weakness predominantly of her face, arms, and neck. Serum antibodies against acetylcholine receptors were 9.9 nmol/L. She was started on pyridostigmine, with significant clinical improvement, reassuming normal daily activities. Two years later, generalized weakness reappeared and reappraisal of her symptomatology disclosed tongue percussion and hand action myotonia. Molecular genetic analysis disclosed 550 repeats of cytosine-thymidine-guanosine triplets on the DMPK gene. Undiagnosed relatives had expansions ranging from 110 to 1000 repeats. Myotonic dystrophy is considered the most common muscular dystrophy, with highly variable clinical manifestations; mildly affected individuals may escape clinical detection. Myasthenia gravis has an estimated prevalence of 15 per 100,000. No studies on the epidemiology of these diseases have been done in Chile. Although both diseases have specific clinical and laboratory presentations, they share some features in the mode of presentation that may generate difficulty in diagnosis of both entities in the same patient.

Neurotomía periférica selectiva en el tratamiento de la espasticidad discapacitante del niño y adolescente / Peripheral selective neurotomy in the treatment of the disabling spasticity in child and adolescent

Abbreviations PSN Peripheral Selective Neurotomy;SEF Spastic Equinus Foot;SHA Spastic Hip Adduction;SHW Spastic Hand-Wrist Introduction.PSN is a microsurgical partial section of motor branches whose aim is supress the monosinaptic tonic stretching reflex leading to reduction of harmful spasticity without excessive paresis, restoring the tonic agonist-antagonist balance in a limb segment.Aims. Assess the benefits of PSN for treatment of disabling spasticity in children and teenager population. Method.19 consecutive patients (68 por ciento males,age 5-23 ), were treated through PSN.10 patients had SEF or SHA, and 9 had SHW.The inclusion criteria were age of 4 years or more; focused disabling spasticity at least grade 2 in Ashworth Mod. Scale; failure of previous non-surgical therapies; duration of spasticity more than 2 years, positive response to the motor anaesthetic block test; no evidence of irreductible muscle contracture. The goals of surgery were to improve function, cosmetics and confort of the affected limb segment. Clinical evaluation of spasticity (Ashworth Modified Scale), articular mobility (Goniometry), Gait (Video and gait analysis), and Prehension (Functional 440 pts. Scale), were performed. Results.The postoperative follow-up period range from 1 to 18 months. Spasticity was reduced in all the muscles denervated. The triceps surae spasticity reduction in SEF patients remain stable over a follow-up period of 6-18 months. 7/9 SEF patients improved ankle active dorsiflexion, ½ SHA improved hip abduction, while a mean improvement of 31.3° in wrist supination and 28.7° in wrist extension was achieved in the SHW group. 8/9 SEF patients showed improvement in 1 or more of the following gait features: ankle dorsiflexion, length of step, gait speed, proximal kinematic segment performance. The prehension improved in 7 patients (78 por ciento).All SHW patients improved their confort and limb cosmetics. 3 patients 15 por ciento) had transient dysesthesia...

Abordaje de la cefalea en niños. preguntas y respuestas / Boarding of the migraine in childrens. questions and answers

Siendo un síntoma frecuente en niños y adolescentes, la evaluación racional de la cefalea parte con una historia completa y cuidadosa. El primer paso es caracterizar este síntoma e identificar el patrón temporal de la cefalea. El paso siguiente es el examen físico y neurológico, con énfasis en el examen del disco óptico, movimientos oculares, búsqueda de asimetría motora o sensitiva, coordinación, marcha y reflejos. Luego de esta etapa, en la mayoría de los casos podemos saber si estamos ante una cefalea primaria o secundaria. La decisión de indicar exámenes de laboratorio y/o neuroimágenes debe ser tomada sólo después de contar con una historia y examen completos que orienten hacia una cefalea secundaria. Las neuroimágenes están indicadas especialmente en niños con cefalea crónica progresiva, cambio del patrón temporal o alteración del examen neurológico. Una vez que el diagnóstico de cefalea está establecido, el manejo futuro se basará, en el caso de las cefaleas secundarias, en la resolución de la causa y en el caso de las cefaleas primarias, en una terapia de acuerdo a la frecuencia y severidad de la cefalea y del impacto que produzca en la calidad de vida del niño, lo que exige un registro cuidadoso de los episodios y factores asociados (calendario de cefaleas).

Enfermedades neuromusculares en pediatría / Neuromuscular diseases in pediatrics

Las enfermedades neuromusculares (ENM) son causa frecuente de morbilidad pediátrica, con una amplia variedad de motivos de consulta, lo que dificulta en ocasiones la aproximación diagnóstica inicial. Dado que muchos de estos trastornos son causa de discapacidad progresiva en el niño, el diagnóstico oportuno es fundamental. Las herramientas más importantes en su estudio son la anamnesis y el examen clínico completo y detallado. Este abordaje eminentemente clínico permite establecer un diagnóstico sindromático, orientar hacia cuadros específicos más probables y dirigir el estudio de laboratorio. El laboratorio neuromuscular incluye una serie de exámenes que ayudan a la identificación de estos cuadros y al diagnóstico diferencial entre fenotipos comunes. Sin embargo su indicación debe ser hecha por el especialista considerando utilidad y limitaciones. Los objetivos del estudio diagnóstico son: establecer un consejo genético, definir el pronóstico aproximado, según las posibilidades terapéuticas disponibles a nivel mundial, y establecer un plan de tratamiento actualizado, orientado a mantener función, prevenir complicaciones y mejorar calidad de vida. Igualmente importante es identificar cuadros que tienen tratamiento específico y que de no tratarse tendrían consecuencias deletéreas en el desarrollo y función motora del niño.

Peripheral nerve conduction abnormalities in children exposed to alcohol in utero.

OBJECTIVE: We performed a longitudinal study of nerve conduction velocity to determine the effect of prenatal alcohol exposure on the peripheral nervous system. Study design We studied 17 children exposed to >2 oz of absolute alcohol/day prenatally and 13 unexposed children, identified prospectively from a cohort of pregnant women screened during prenatal care. Nerve conduction assessment was done on the median, ulnar, peroneal and tibial nerves during the newborn period and between 12 and 14 months of age. RESULTS: At both assessments the alcohol-exposed subjects had significantly slower ulnar motor nerve velocity (P=.007), smaller proximal (P=.018) and distal amplitude (P=.051). They also showed reduced tibial nerve velocity (P=.06) and a decrease in distal amplitude. CONCLUSIONS: This study demonstrates that prenatal alcohol exposure is associated with abnormalities in nerve electrical properties, and that the pattern is different from that seen in adults. Electrophysiologic abnormalities in peripheral nerves should be added to the problems found in children of alcohol abusing mothers.