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?Autismo! por Sarah Stuntebeck, MS, CCC-SLP, y Luke Fortney, MD

Por 1 de octubre de 2013 #!31Fri, 31 Jul 2020 04:23:16 -0800p1631#31Fri, 31 Jul 2020 04:23:16 -0800p-4-08:003131-08:00x31 31am31am-31Fri, 31 Jul 2020 04:23:16 -0800p4-08:003131-08:00x312020Fri, 31 Jul 2020 04:23:16 -0800234237amFriday=3557#!31Fri, 31 Jul 2020 04:23:16 -0800p-08:007#July 31st, 2020#!31Fri, 31 Jul 2020 04:23:16 -0800p1631#/31Fri, 31 Jul 2020 04:23:16 -0800p-4-08:003131-08:00x31#!31Fri, 31 Jul 2020 04:23:16 -0800p-08:007# Sin comentarios

La historia de los trastornos del espectro autista (TEA) es ?nica en comparaci?n con otros trastornos, ya que pocos han visto un aumento tan inexplicable con el tiempo, la presi?n sobre los recursos personales y de atenci?n m?dica, el aumento del activismo social y las organizaciones de defensa, y los enfoques de tratamiento controvertidos. Reportado por primera vez en 1943, el autismo plantea desaf?os particulares para los investigadores dados los numerosos factores que contribuyen. Aunque tratable, se considera un trastorno incurable y multifactorial que est? influenciado por aspectos gen?ticos, neurol?gicos, ambientales e inmunol?gicos.1 Dicho esto, los desarrollos recientes han ayudado a crear una mejor comprensi?n de la heterogeneidad de los TEA y sus fenotipos variables.2

Autism itself is a biologically based disorder of brain development. This neurodevelopmental disorder is characterized by variable degrees of social and language deficits. Children with ASD demonstrate stereotypically restricted and repetitive behavior. Variants of ASD include conditions such as pervasive developmental delay (PDD) and Asperger disorder (AD). A 2012 Centers for Disease Control and Prevention (CDC) report estimates that of all autism diagnoses in the United States, 47% were PDD and 9% were AD.3 Comorbid conditions such as ADHD on the other hand are separate but appear to have a higher prevalence in ASD.

La incidencia de TEA ha aumentado 10 veces en los ?ltimos 25 a?os. En 1990, la prevalencia estimada era de 5 por cada 10.000 ni?os. Un informe publicado por el Departamento de Salud y Servicios Humanos de EE. UU. Indica que entre los ni?os de 6 a 17 a?os, la prevalencia del autismo aument? de 1.16% en 2007 a 2.00% en 2012,4, aunque los CDC estiman que uno de cada 110 ni?os que ahora nacieron en el Estados Unidos tiene ASD.5

Aunque existe una controversia con respecto a los diversos factores que pueden contribuir a la prevalencia y gravedad de los TEA, quiz?s el aspecto m?s frustrante de los TEA tanto para los padres como para los profesionales de la salud es que sus causas siguen siendo desconocidas. Dicho esto, la mayor?a de los expertos est?n de acuerdo en que ASD es un trastorno gen?ticamente predispuesto que parece requerir un desencadenante (o desencadenantes) ambientales incitantes. Para la mayor?a de los casos de TEA, no se ha demostrado definitivamente que un solo gen o grupo de genes afecte significativamente su desarrollo. Sin embargo, hay una concordancia 90% entre gemelos id?nticos frente a 30% en gemelos fraternos.

The pathophysiology of autism is without surprise not well understood. A genetic cause can be identified in only 20% of ASD cases, involving genes that converge on common pathways that alter synaptic homeostasis.7 There is good evidence to support the understanding that autism is characterized by inflammatory and abnormal neural connections, particularly underconnectivity of cortical systems leading to abnormal interhemispheric communication. With corroborating advanced imaging from fMRI, this abnormal brain function correlates well with many of the stereotypical behaviors seen in ASD.8

Intestino disfuncional
One of the most widely debated aspects of ASD is gastrointestinal (GI) dysregulation specifically conditions known as dysbiosis and increased intestinal permeability. However, the exact cause for increased prevalence of GI abnormalities in ASD is unknown. Up to one-third of children with autism exhibit some form of GI disorder clinically (e.g., constipation, abdominal pain, diarrhea, gastroesophageal reflux disease). The human gut is home to a dynamic and complex community of microbes that can profoundly influence nervous system growth and development.9 Many of the behavioral challenges associated with autism likely can be explained by gut dysfunction, noting that many autistic children have communication barriers and have challenges expressing their discomfort.

Un estudio encontr? que los ni?os con TEA tratados con vancomicina vieron una mejora tanto en las bacterias intestinales anormales como en los s?ntomas gastrointestinales, al tiempo que observaron mejoras en el comportamiento autista.10 Las pruebas de lactulosa-manitol revelan que la mayor?a de estos ni?os exhiben permeabilidad intestinal anormal, lo que se cree que indican atrofia de la mucosa intestinal y lesiones en las uniones intercelulares. Se cree que esta alteraci?n de la permeabilidad intestinal permite la absorci?n de p?ptidos digeridos de forma incompleta que se comportan como agonistas de los receptores que conducen a una neuroactividad cerebral-intestinal anormal que produce cambios de comportamiento.11

Along these lines, duodenal biopsies from 25 autistic children show increased lymphocytic proliferation and other immune abnormalities, indicating a possible autoimmune etiology.12 A separate study of 36 autistic children reported significantly higher levels of IgG, IgM, and IgA to food proteins such as casein and lactoglobulin compared to controls.13 An autoimmune etiology in ASD is supported by an epidemiological study showing that families affected by autism had 1.87 relatives with autoimmune disorders, which is significantly more common when compared to the general population, and surprisingly even more common than families affected by other common autoimmune diseases such as lupus and rheumatoid arthritis.14 Another study even found that 36.7% of autistic patients and 21.2% of their direct relatives demonstrated active leaky gut syndrome as compared to 5% of controls.15 These findings suggest an inheritable predisposition for ASD that, when triggered by environmental events, may play a key role in prevalence and severity.

DIETA SIN GLUTEN / CASEIN-FREE
The majority of published studies show a statistically significant benefit of a gluten-free/casein-free (GFCF) diet in ASD. However, specific characteristics of best and non-responders to GFCF intervention have not yet been elucidated. That some children benefit from this dietary intervention and others do not is likely due to variable ASD phenotypes.16 One striking case report in the literature reported significant benefits in a child with severe ASD, morbid obesity, and epilepsy, who after limited response to other interventions, was placed on a GFCF-ketogenic diet that used medium-chained triglycerides and a high intake of vegetables. Over the course of a few years, the child's Autism Rating Score went from severe to non-autistic, her intelligence quotient increased 70 points, and she became seizure-free with normal follow-up EEGs.17 Needless to say, in keeping with the favorable benefit-harm ratio, it is entirely reasonable for families affected by ASD to implement a GFCF diet.

Adem?s, muchos estudios demuestran la necesidad de complementar la dieta de pacientes autistas con ?cidos grasos omega-3, probi?ticos, vitaminas y minerales en combinaci?n con otras intervenciones m?dicas y psicol?gicas.18 Sin embargo, los buenos datos muestran un beneficio cl?nico concluyente de estas adiciones en gran medida faltan y ha habido llamados para investigar el probable papel beneficioso de los probi?ticos en ASD.19

MERCURIO Y TOXINAS AMBIENTALES
Otro sospechoso popular de ASD es el timerisol (etilmercurio), que anteriormente estaba contenido en las vacunas infantiles. Esto, quiz?s m?s que cualquier otro aspecto de la historia del autismo, ha sido objeto de acalorados debates. Una revisi?n de la FDA encontr? que antes de 1999, la suma aditiva de las vacunas infantiles exced?a los l?mites de la EPA para la exposici?n segura de metilmercurio. Aunque los estudios epidemiol?gicos no han logrado encontrar una conexi?n entre las peque?as cantidades de mercurio en las vacunas y la incidencia de ASD, 20 un estudio demostr? un aumento asociado de 61% en la tasa de incidencia de autismo por cada 1000 libras de mercurio liberado de la contaminaci?n industrial.21

Existe una preocupación constante por el creciente entorno químico al que están expuestos los niños a una edad temprana. Una fuente bien conocida de exposición al mercurio proviene de los empastes de amalgama. Sin embargo, si hay algún efecto adverso en la salud de esto sigue siendo un tema de debate.22 Si bien el mercurio es una neurotoxina bien conocida sin un nivel aceptable de exposición, no se ha demostrado que sea una causa importante de autismo por sí misma. Sin embargo, el mercurio puede ser la punta del iceberg. Los niños de hoy están expuestos a miles de productos químicos sintéticos, con al menos 200 neurotoxinas conocidas y otros 1000 que demuestran neurotoxicidad en pruebas de laboratorio. Según el programa de biomonitoreo de los CDC, hay más de 100,000 productos químicos que se usan comúnmente todos los días en productos de limpieza para el hogar, solventes, pesticidas, aditivos alimentarios, cuidado del césped y otros productos. Cada año se introducen otros 1000 productos químicos que no tienen en cuenta las mezclas y diversas combinaciones de productos comerciales y de consumo a los que están expuestas las personas23.

Another alarming study found nearly 300 environmental toxins in the umbilical blood of neonates.24 Animal models show that even low levels of these toxins can negatively affect neurodevelopment. Indirect human evidence points to the sensitivity of the developing brain to lead, mercury, and other toxins. The strongest proof-of-concept evidence comes from research linking ASD to various chemical exposures in early pregnancy.25 Given this information, it is reasonable for parents and practitioners alike to follow the precautionary principle that states, When an activity raises threats of harm to human health or the environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. 26

Dicho esto, se ha postulado que los defectos metab?licos hereditarios previamente no detectados predisponen a aquellos que eventualmente ser?an diagnosticados con TEA debido a sistemas de desintoxicaci?n deteriorados que no son capaces de manejar adecuadamente el mismo bajo nivel de exposici?n t?xica que los ni?os con desarrollo normal. Por ejemplo, en un estudio de m?s de 200 ni?os autistas tratados con el agente quelante DMSA, los niveles urinarios de mercurio fueron significativamente m?s altos en comparaci?n con los controles neurot?picos.27 Estudios adicionales respaldan la hip?tesis de que, aunque los ni?os con autismo y neuropat?a los ni?os t?picos tienen exposiciones similares, 28 aquellos con TEA exhiben niveles anormales de porfirina urinaria, lo que indica un metabolismo y eliminaci?n anormales del mercurio29.

Although children with ASD may be susceptible to even normal levels of mercury exposure, and although there are some data showing increased urinary output of toxic metals with use of chelating agents,30 evidence showing clinically beneficial outcomes from the use of chelating agents such as EDTA and DMSA is lacking.31 What s more, NIH-funded trials were halted prematurely due to ethical concerns.32 However, there are reasonable lifestyle approaches to help reduce toxic body burden for would-be-mothers and families with young children (see EWG link in resources).

VACUNAR O NO VACUNAR: EL CASO DE MMR
La vacuna MMR ha sido implicada por muchos padres como un evento desencadenante del autismo. Aunque hubo inquietudes iniciales, no se ha encontrado ning?n v?nculo entre la vacuna MMR y el autismo.33 De hecho, un estudio reciente encontr? que los ni?os con TEA tienen niveles similares de anticuerpos contra la vacuna MMR que los controles neurot?picos de la misma edad. infame estudio publicado en el Lanceta in 1998 that suggested a link in ASD with colitis and MMR vaccination35 was retracted in 2010 by the journal due to serious irregularities.36 An 8-year U.S. federal court process that finally ended in 2010 concluded that ASD was not caused by an adverse reaction to vaccination.37 To the contrary, it is now estimated that MMR vaccinations administered in the United States from 2001-2010 helped prevent more than 16,000 cases of congenital rubella syndrome a known cause of ASD which in turn helped prevent more than 6000 new cases of ASD during that 10-year period.38

Las retractaciones de los estudios y las sentencias judiciales apenas han transformado el pensamiento de muchos grupos de defensa contra las vacunas. Una historia reciente de CNN inform? que las infecciones de sarampi?n, una vez consideradas erradicadas en los Estados Unidos, han aumentado.39 Por ejemplo, otra historia de NPR inform? que 21 feligreses esc?pticos a las vacunas de una Iglesia del Norte de Texas que no hab?an sido inmunizados adecuadamente con MMR estaban infectados en un brote de sarampi?n40. Como referencia, se estima que 1 de cada 1000 ni?os muere en ?ltima instancia de infecciones de sarampi?n, incluso con el mejor cuidado.39 Como resultado, ha habido llamados a dejar de lado las disputas filos?ficas y en su lugar responder con empat?a y abrir un di?logo centrado en la familia para abordar la informaci?n err?nea y las preocupaciones sobre las vacunas.41

Alternative childhood immunization schedules (ACIS) are one approach for families that refuse standard CDC vaccine schedules. Despite controversy of a well-known ACIS (the Sears alternative vaccine schedule42), a recent survey of 517 families in Washington found that this approach did not predominate, with only 9.4% of parents reporting use of ACIS.43 The real advantage of offering ACIS to concerned parents is not about efficacy or promoting a better or worse vaccination schedule, but rather in establishing a trusting relationship while ensuring eventual full immunization and protection for children.

TERAPIAS DE COMPORTAMIENTO Y DISCURSO PARA TEA
Although the cause(s) of autism are unknown, there are reasonable and effective treatments for ASD. The most common, and arguably the most effective approaches address behavioral, communication, and social deficits. Early screening during routine well-child exams can identify signs of ASD, which in turn should lead to initiation of speech-language therapy (see NICHCY link in resources). Effective services should vary with individual children, depending on the child's age, cognitive level, language skills, behavioral needs, and family priorities. With some children, it is appropriate to incorporate augmentative and alternative communication (AAC), such as the Picture Exchange Communication System, other high- and low-tech assistive technology tools, and/or sign language. A meta-analysis of single-case research studies indicates strong effects for the use of AAC on communication skills. Although effect sizes should be interpreted cautiously due to the small number of studies, social skills, challenging behaviors, and spelling also appear to be positively affected.44

Although behavioral intervention methods appear to have a positive impact on learning, communication, and behavior in children with ASD, intervention studies suffer from methodological problems that make it difficult to form definitive conclusions regarding efficacy. That being said, there is evidence to support the use of applied behavioral analysis for functional skills development, and there are clear benefits of Lovaas therapy compared to no treatment. Furthermore, increased therapy intensity is known to be more effective than no- or low-intensity therapy. The National Research Council suggests that young children with ASD should receive at least 25 hours of individualized and structured intervention per week, 12 months a year.45 In general though, as no definitive behavioral or developmental intervention improves all symptoms for every child, it is recommended that therapy management be guided by each child's needs and availability of resources.46

Otras terapias conductuales comunes y efectivas incluyen el Modelo de relación de diferencia individual de desarrollo y Floortime de Greenspan, que incorpora actividades de juego con énfasis en el desarrollo emocional. La Intervención de Desarrollo de Relaciones es un enfoque de tratamiento basado en los padres que trabaja para mejorar las habilidades sociales, la adaptabilidad y las habilidades de autoconciencia. La comunicación social / regulación emocional / apoyo transaccional utiliza prácticas de una variedad de otros enfoques para promover la comunicación y las habilidades iniciadas por los niños en una variedad de entornos.

Although there are anecdotal reports of benefits from sensory motor interventions, such as sensory integration therapy or use of a sensory diet, results are limited and inconsistent. A review of auditory integration therapy by the American Speech-Language and Hearing Association concluded that efficacy standards for use by audiologists and speech-language pathologists are not yet available. At this time, families should pursue these therapies with some skepticism until further research can be conducted.47 n

Referencias
1. Al-Ayadhi L, et al. Role of proteomics in the discovery of autism biomarkers. J Coll Physicians Surg Pak 2013;23:137-143.

2. Thompson T. Autism research and services for young children: History, progress, and challenges. J Appl Res Intelecto Disabil 2013;26:81-107.

3. Centers for Disease Control and Prevention. Prevalence of autism spectrum disorders Autism and Developmental Disabilities Monitoring Network, 14 sites, United States, 2008. MMWR Surveill Summ 2012;61:10.

4. Blumberg S, et al. Changes in prevalence of parent-reported autism spectrum disorder in school-aged U.S. children: 2007 to 2011-2012. Informes nacionales de estad?sticas de salud 2013;65:1-11.

5. CDC: National Center on Birth Defects and Developmental Disabilities: How Many Children Have Autism Available at: www.cdc.gov/ncbddd/features/counting-autism.html. Accessed Sept. 2, 2013.

6. El-Fishawy P, State MW. The genetics of autism: Key issues, recent findings, and clinical implications. Psychiatr Clin North Am 2010;33:83-105.

7. Delorme R, et al. Progress toward treatments for synaptic defects in autism. Nat Med 2013;19:685-694.

8. Minshew NJ, Keller TA. The nature of brain dysfunction in autism: Functional brain imaging studies. Curr Opin Neurol 2010;23:124-130.

9. Mulle JG, et al. The gut microbiome: A new frontier in autism research. Representante de Psiquiatr?a de Curr 2013;15:337.

10. Sandler RH, et al. Short-term benefit from oral vancomycin treatment of regressive-onset autism. J Neurol infantil 2000;15:429-435.

11. Souza NC, et al. Intestinal permeability and nutritional status in developmental disorders. Altern Ther Health Med 2012;18:19-24.

12. Torrente F, et al. Small intestinal enteropathy with epithelial IgG and complement deposition in children with regressive autism. Psiquiatr?a Mol 2002;7:375-382.

13. Lucarelli S, et al. Food allergy and infantile autism. Panminerva Med 1995;37:137-141.

14. Sweeten TL, et al. Increased prevalence of familial autoimmunity in probands with pervasive developmental disorders. Pediatr 2003; 112: e420.

15. de Magistris L, et al. Alterations of the intestinal barrier in patients with autism spectrum disorders and in their first-degree relatives. J Pediatr Gastroenterol Nutr 2010;51:418-424.

16. Whiteley P, et al. Gluten- and casein-free dietary intervention for autism spectrum conditions. Front Hum Neurosci 2013;4:344.

17. Herbert MR, et al. Autism and dietary therapy: Case report and review of the literature. J Neurol infantil 2013;28:975-982.

18. Kawicka A, et al. How nutritional status, diet and dietary supplements can affect autism. A review. Rocz Panstw Zakl Hig 2013;64:1-12.

19. Critchfield JW, et al. The potential role of probiotics in the management of childhood autism spectrum disorders. Gastroenterol Res Pract 2011; Epub 2011; 26 de octubre.

20. Madsen KM, et al. Thimerosal and the occurrence of autism: Negative ecological evidence from Danish population-based data. Pediatr 2003; 112 (3 Pt 1): 604-606.

21. Palmer RF, et al. Environmental mercury release, special education rates, and autism disorder: An ecological study of Texas. Lugar de salud 2006;12:203-209.

22. Park JD, Zheng W. Human exposure and health effects of inorganic elemental mercury. J Prev Med Salud P?blica 2012;45:344-352.

23. CDC Agency for toxic substances and disease registry. Available at: www.atsdr.cdc.gov/risk/cancer/cancer-laboratory.html. Accessed Sept. 3, 2013.

24. Environmental Working Group: Body Burden: The Pollution in Newborns. A Benchmark Investigation of Industrial Chemicals, Pollutants, and Pesticides in Umbilical Cord Blood 2005. Available at: www.ewg.org/research/body-burden-pollution-newborns. Accessed Sept. 8, 2013.

25. Landrigan PJ. What causes autism Exploring the environmental contribution. Curr Opin Pediatr 2010;22:219-225.

26. Precautionary Principle. Available at: www.sehn.org/precaution.html. Accessed Sept. 3, 2013.

27. Bradstreet J, et al. A case-control study of mercury burden in children with autistic spectrum disorders. J Am Phys Surg 2003;8:76-82.

28. Albizzati A, et al. Normal concentrations of heavy metals in autistic spectrum disorders. Minerva Pediatr 2012;64:27-31.

29. Woods JS, et al. Urinary porphyrin excretion in neurotypical and autistic children. Perspectiva de salud ambiental 2010;118:1450-1457.

30. Blaucok-Busch E, et al. Efficacy of DMSA therapy in a sample of Arab children with autistic spectrum disorder. Maedica (Buchar) 2012; 7: 214-221.

31. Wadman M. Autism study panned by critics. Naturaleza 2008;453:259.

32. Mitka M. Chelation therapy trials halted. Jamaica 2008;300:2236.

33. Mrozek-Budzyn D, et al. Lack of association between measles-mumps-rubella vaccination and autism in children: A case-control study. Pediatr Infect Dis J 2010;29:397-400.

34. Gentile I, et al. Response to measles-mumps-rubella vaccine in children with ASD. En vivo 2013;27:377-382.

35. Wakefield A, et al. Ileal-lymphoid-nodular hyperplasia, non-specific colitis, and pervasive developmental disorder in children. Lanceta 1998;351:637-641.

36. Harris G. Journal retracts 1998 paper linking autism to vaccines. New York Times. Disponible en: www.nytimes.com/2010/02/03/health/research/03lancet.html _r = 0. Consultado el 8 de septiembre de 2013.

37. Kirkland A. Credibility battles in the autism litigation. Soc Stud Sci 2012;42:237-261.

38. Berger BE, et al. Congenital rubella syndrome and autism spectrum disorder prevented by rubella vaccination United States, 2001-2010. BMC Public Health 2011;11:340.

39. CNN Health. US measles cases in 2013 may be most in 17 years. Available at: www.cnn.com/2013/09/12/health/worst-measles-year/index.html hpt=he_c2. Accessed Sept. 3, 2013.

40. NPR News. Texas megachurch at center of measles outbreak. Available at: www.npr.org/2013/09/01/217746942/texas-megachurch-at-center-of-measles-outbreak. Accessed Sept. 3, 2013.

41. Holler K, et al. I've heard some things that scare me. Responding with empathy to parents fears of vaccinations. Mo Med 2012;109:10-13.

42. Offit PA, et al. The problem with Dr. Bob s alternative vaccine schedule. Pediatr 2009;123:164-169.

43. Opel DJ, et al. Use of alternative childhood immunization schedules in King County, Washington, USA. Vacuna 2013; 24 de agosto. Pii: S0264-410X (13) 01127-4. doi: 10.1016 / j.vaccine.2013.08.036. [Epub antes de la impresi?n].

44. Ganz JB, et al. A meta-analysis of single case research studies on aided augmentative and alternative communication systems with individuals with autism spectrum disorders. J Autism Dev Disord 2012;42:60-74.

45. Educating Children with Autism. Lord & McGee, eds Washington DC. National Academy Press, National Research Council. Division of Behavioral and Social Sciences. 2001.

46. Ospina MB, et al. Behavioural and developmental interventions for autism spectrum disorder: A clinical systematic review. M?s uno 2008; 3: e3755.

47. American Speech-Language-Hearing Association. Auditory integration training Position Statement. Available at: www.asha.org/policy. Accessed Sept. 8, 2013.

La Sra. Stuntebeck es profesora asistente cl?nica del Departamento de Ciencias de la Comunicaci?n y Trastornos de la Universidad de Wisconsin-Madison. El Dr. Fortney es m?dico de medicina familiar integradora, Meriter Medical Group, Madison, Wisconsin.

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