Cuidados respiratorios de los pacientes con atrofia muscular espinal / Respiratory care approach for patients with spinal muscular atrophy

Spinal Muscular Atrophy (SMA) is a disease of the anterior horn of the spinal cord, which causes muscle weakness that leads to a progressive decrease in vital capacity and diminished cough flows. Respiratory morbidity and mortality are a function of the degree of respiratory and bulbar-innervated muscle. The former can be quantitated by the sequential evaluation of vital capacity to determine the lifetime maximum (plateau) and its subsequent rate of decline, progressing to ventilatory failure. SMA types 1 and 2 benefit from non-invasive respiratory care in early childhood and school age, improving quality and life expectancy. This document synthesizes these recommendations with special reference to interventions guided by stages that include air stacking, assisted cough protocols, preparation for spinal arthrodesis and non-invasive ventilatory support, even in those patients with loss of respiratory autonomy, minimizing the risk tracheostomy. Failure to consider these recommendations in the regular assessment of patients reduces the offer of timely treatments.

La Atrofia Muscular Espinal (AME) es una enfermedad genética del asta anterior de la medula espinal, que cursa con debilidad muscular progresiva. La intensidad y precocidad de la debilidad muscular presenta diferentes grados de afectación de los grupos musculares respiratorios, determinando la meseta en la capacidad vital y progresión a la insuficiencia ventilatoria, como también el compromiso de los músculos inervados bulbares. Los AME tipo 1 y 2, se benefician con cuidados respiratorios no invasivos en la infancia temprana y edad escolar, mejorando la calidad y esperanza de vida. Este documento sintetiza dichas recomendaciones, con especial referencia a intervenciones guiadas por etapas, que incluyan apilamiento de aire, protocolos de tos asistida, preparación para la artrodesis de columna y soporte ventilatorio no invasivo, incluso en aquellos pacientes con pérdida de la autonomía respiratoria, minimizando el riesgo de traqueostomía. La no consideración de estas recomendaciones en la valoración regular de los pacientes resta la oferta de tratamientos oportunos.

Perfil demográfico y clínico-funcional de pacientes con atrofia muscular espinal atendidos en el Instituto Teletón Santiago / Demographic and clinical-functional profile of patients with spinal muscular atrophy attending Instituto Teletón Santiago

Introducción: La atrofia muscular espinal (AME) es una enfermedad neuromuscular (ENM) severa caracterizada por la degeneración de las motoneuronas alfa del asta anterior de la médula espinal, generando una debilidad progresiva de la musculatura proximal. La incidencia mundial se estima en 1/6.000-10.000 nacidos vivos. Contamos con escasos datos de las características de los pacientes con AME en la población chilena. Objetivo: Determinar magnitud, características demográficas y clínico funcionales de los pacientes con AME atendidos en el Instituto Teletón Santiago (ITS). Pacientes y Método: Estudio descriptivo transversal, basado en revisión del sistema informático ITS, fichas clínicas y encuesta telefónica. Resultados: Se identificaron 62 pacientes con AME con controles en ITS, 49 (79%), fueron incluidos. 30,6%, 36,7% y 32,7% corresponden a pacientes con AME 1, 2 y 3 respectivamente. Edad promedio 10,6 ± 6,6 años; pérdida de marcha edad mediana de 6,8 años en pacientes AME 3. 67,3% requieren algún tipo de asistencia ventilatoria, 44,9% presentan trastornos de deglución, 75,5% escoliosis, 49,0% subluxación o luxación de cadera, 79,6% retracciones articulares y 65,3% dolor. En participación, el 83% de las actividades de ocio se realizan dentro del hogar, principalmente de tipo tecnológico; 77,5% realiza salidas sociales. Conclusión: Las características clínico funcionales de los pacientes con AME, evidencian un grupo que presenta un alto nivel de dependencia en todos los tipos de la enfermedad, múltiples comorbilidades y alteraciones músculo-esqueléticas secundarias y por ello requiere de un programa de rehabilitación multidisciplinaria tal como lo describe la literatura internacional.

Introduction: Spinal muscular atrophy (SMA) is a severe neuromuscular disease (NMD) characterized by the loss of alpha motor neurons of the anterior horn of the spinal cord, causing progressive weakness of proximal muscles. Global prevalence is estimated to be 1/6,000-10,000 live births. There is limited data on SMA patients in the Chilean population. Objective: To establish the scale, demographics and functional-clinical characteristics of SMA patients attending Instituto Teletón Santiago (ITS). Patients and Method: Cross-sectional, descriptive study based on the review of ITS's data information system, clinical records and telephone surveys. Results: 62 SMA patients were identified attending regular controls at ITS, 49 (79%) were included in the study. 30.6%, 36.7% and 32.7% correspond to SMA 1, 2 or 3, respectively. Average age 10.6 ± 6.6 years; loss of gait at a median age of 6.8 years in SMA 3 patients. 67.3% require some type of breathing assistance, 44.9% have swallowing problems, 75.5% scoliosis, 49% hip dislocation or subluxation, 79.6% contracture of joints and 65.3% pain. In terms of social participation, 83% of recreational activities are carried out indoors, mainly related to the use of technology; and 77.5% go out to take part in social activities. Conclusion: Functional-clinical characteristics of SMA patients show that there is a group with high levels of dependence in all types of the disease, multiple concurrent disorders and secondary musculoskeletal conditions, and therefore, in the necessity to have a multidisciplinary rehabilitation system, as described in international literature.

Escala de evaluación funcional de extremidades superiores en niños con distrofia muscular de Duchenne y Atrofia músculo espinal / Upper limb functional assessment scale for children with Duchenne muscular dystrophy and Spinal muscular atrophy

La distrofia muscular de Duchenne (DMD) y la Atrofia músculo espinal (AME) determinan discapacidad y compromiso funcional progresivo. Se requiere de instrumentos fácilmente disponibles, que evalúen la funcionalidad, especialmente en etapas avanzadas de la enfermedad, para monitorizar evolución e impacto de intervenciones terapéuticas. Objetivo: Reportar el desarrollo de escala para evaluar la función de las extremidades superiores (EESS) en pacientes con DMD y AME, y describir su proceso de validación que incluye autoentrenamiento para evaluadores. Pacientes y Método: El desarrollo de la escala incluyó revisión de escalas publicadas, aplicación exploratoria de escala inicial en niños sanos y con DMD, autoentrenamiento de evaluadores en aplicación de escala definitiva utilizando manual y vídeo tutorial y aplicación de escala en grupo de niños con DMD y AME. Se evaluó confiabilidad con coeficiente de Cronbach y de Kendall y concordancia con test-retest intra e inter-evaluadores, y validez con análisis de concordancia y factorial. Resultados: Se observó alto grado de confiabilidad, con alta consistencia interna (a de Cronbach = 0,97) y concordancia interevaluadores (W de Kendall = 0,96) e intraevaluadores (r = 0,97 a 0,99). La validez se demostró por la inexistencia de diferencias significativas entre resultados de distintos evaluadores con evaluador experto (F = 0,023, p > 0,5) y análisis factorial, que mostró que 4 factores explican el 85,44% de varianza total. Conclusiones: Esta escala de evaluación es un instrumento confiable y válido para evaluar la funcionalidad de EESS en niños con DMD y AME. Además, es de fácil implementación por la posibilidad de autoentrenamiento y el uso de materiales simples y de bajo costo.

Duchenne muscular dystrophy (DMD) and Spinal muscular atrophy (SMA) causes significant disability and progressive functional impairment. Readily available instruments that assess functionality, especially in advanced stages of the disease, are required to monitor the progress of the disease and the impact of therapeutic interventions. Objective: To describe the development of a scale to evaluate upper limb function (UL) in patients with DMD and SMA, and describe its validation process, which includes self-training for evaluators. Patients and Method: The development of the scale included a review of published scales, an exploratory application of a pilot scale in healthy children and those with DMD, self-training of evaluators in applying the scale using a handbook and video tutorial, and assessment of a group of children with DMD and SMA using the final scale. Reliability was assessed using Cronbach and Kendall concordance and with intra and inter-rater test-retest, and validity with concordance and factorial analysis. Results: A high level of reliability was observed, with high internal consistency (Cronbach a = 0.97), and inter-rater (Kendall W = 0.96) and intra-rater concordance (r = 0.97 to 0.99). The validity was demonstrated by the absence of significant differences between results by different evaluators with an expert evaluator (F = 0.023, p > .5), and by the factor analysis that showed that four factors account for 85.44% of total variance. Conclusions: This scale is a reliable and valid tool for assessing UL functionality in children with DMD and SMA. It is also easily implementable due to the possibility of self-training and the use of simple and inexpensive materials.

Air stacking: effects on pulmonary function in patients with spinal muscular atrophy and in patients with congenital muscular dystrophy, / Efeitos do treinamento de empilhamento de ar na função pulmonar de pacientes com amiotrofia espinhal e distrofia muscular congênita

OBJECTIVE: Respiratory complications are the main causes of morbidity and mortality in patients with neuromuscular disease (NMD). The objectives of this study were to determine the effects that routine daily home air-stacking maneuvers have on pulmonary function in patients with spinal muscular atrophy (SMA) and in patients with congenital muscular dystrophy (CMD), as well as to identify associations between spinal deformities and the effects of the maneuvers. METHODS: Eighteen NMD patients (ten with CMD and eight with SMA) were submitted to routine daily air-stacking maneuvers at home with manual resuscitators for four to six months, undergoing pulmonary function tests before and after that period. The pulmonary function tests included measurements of FVC; PEF; maximum insufflation capacity (MIC); and assisted and unassisted peak cough flow (APCF and UPCF, respectively) with insufflations. RESULTS: After the use of home air-stacking maneuvers, there were improvements in the APCF and UPCF. In the patients without scoliosis, there was also a significant increase in FVC. When comparing patients with and without scoliosis, the increases in APCF and UPCF were more pronounced in those without scoliosis. CONCLUSIONS: Routine daily air-stacking maneuvers with a manual resuscitator appear to increase UPCF and APCF in patients with NMD, especially in those without scoliosis. .

OBJETIVO: As complicações respiratórias são as principais causas de morbidade e mortalidade em pacientes com doenças neuromusculares (DNM). Os objetivos deste estudo foram determinar os efeitos que o treinamento diário domiciliar com manobras de empilhamento de ar tem na função respiratória de pacientes com amiotrofia espinhal (AE) e distrofia muscular congênita (DMC), e identificar possíveis associações entre deformidades na coluna vertebral e os efeitos das manobras. MÉTODOS: Dezoito pacientes com DNM (dez com DMC e oito com AE) foram submetidos a treinamento diário domiciliar de empilhamento de ar com ressuscitador manual por um período de quatro a seis meses e submetidos a testes de função pulmonar antes e após tal período. Os testes de função pulmonar incluíram medidas de CVF, PFE, a capacidade de insuflação máxima (CIM) e a medida do pico de fluxo de tosse não assistido e assistido (PFTNA e PFTASS, respectivamente). RESULTADOS: Após o uso das manobras de empilhamento de ar no domicílio, houve uma melhora significativa na PFTNA e PFTASS. Nos pacientes sem escoliose, houve também um aumento significativo na CVF. No grupo de pacientes sem escoliose, o ganho na PFTNA e PFTASS foi superior ao do grupo com escoliose. CONCLUSÕES: A utilização rotineira diária de manobras de empilhamento de ar com ressuscitador manual parece melhorar a PFTNA e PFTASS em pacientes com DNM, especialmente naqueles sem escoliose. .

Atrofia muscular espinal: Caracterización clínica, electrofisiológica y molecular de 26 pacientes / Clinical, electrophysiological and molecular study of 26 chilean patients with spinal muscular atrophy

Background: Spinal Muscular Atrophy (SMA) is an autosomal recessive disorder affecting the anterior horn cells of the spinal cord resulting in muscle weakness and atrophy, linked to the homozygous disruption of the survival motor neuron 1 (SMN1) gene. It is the leading genetic cause of infant death. It has been classified into three types based on the severity of symptoms. Type I SMA is the most severe form with death within the first 2 years of life. Type II and III SMA patients show intermediate and mild forms of the disorder. Aim: To describe the clinical and electrophysiological findings of 26 Chilean patients with SMA with molecular confirmation. Patients and Methods: Retrospective multicenter analysis of patients with SMA assessed between 2003 and 2010. The diagnosis was suspected on clinical and electrophysiological criteria. Since 2006 molecular genetics confirmation was implemented in one of our centers. Results: Twenty-six patients between 2 months and 18 years of age at presentation were analyzed; 15 (58 percent) were males. SMA I, II and III clinical criteria were observed in 4 (15.4 percent), 11 (42.3 percent) and 11 (42.3 percent)patients, respectively. All had proximal muscle weakness and atrophy. Electromyography showed features of acute denervation or re-innervation with normal motor and sensory nerve conduction. Nine patients required a muscle biopsy. The genetic confirmation of the disease by PCR technique followed by restriction fragment length polymorphism method disclosed the SMN1 gene deletion in all 26 cases. All patients died secondary to respiratory failure, between eight and 14 months of life. Conclusions: An adequate clinical and molecular diagnosis of spinal muscular atrophy will help for a better management of these patients.

Validação da escala motora funcional EK para a língua portuguesa / Validation of the EK functional motor scale in the Portuguese language

OBJETIVO: Validar uma versão traduzida para o português da escala funcional EK (Egen Klassifikation), desenvolvida na Dinamarca, visando aplicação em pacientes com distrofia muscular de Duchenne e atrofia muscular espinhal. MÉTODOS: Uma versão em inglês da escala EK foi traduzida para o português falado no Brasil. Tal escala foi aplicada a 26 pacientes do sexo masculino (idade média = 12,7 ± 4,0 anos), com diagnóstico de distrofia muscular de Duchenne. Os pacientes também responderam questões referentes a uma versão em língua portuguesa do índice de Barthel e tiveram medidas a força de preensão palmar direita e esquerda, com emprego de um dinamômetro de mão. Os escores da escala EK foram correlacionados com a idade, escores do índice de Barthel e as forças palmares. RESULTADOS: O escore total médio da escala EK foi de 8,1 ± 7,3 e do índice de Barthel de 54,0 ± 26,2. A força de preensão palmar direita foi de 12,7 ± 17,2 por cento e a esquerda de 14,6 ± 19,8 por cento do previsto. Os escores da escala EK correlacionaram-se de maneira altamente significante com a idade (r= 0,596, p= 0,0013), força de preensão palmar direita (r= -0,556, p= 0,0032) e esquerda (r= -0,623, p=0,0007), e com o índice de Barthel (r= -0,928, p < 0,0001). CONCLUSÃO: A presente versão em português da escala EK é um instrumento adequado para emprego em pacientes com distrofia muscular de Duchenne brasileiros.

OBJECTIVE: To validate a Portuguese version of the EK scale (Egen Klassifikation), that was developed in Denmark for patients with Duchenne muscular dystrophy, and spinal muscular atrophy. METHODS: An English version of the EK scale was translated into the Portuguese language as spoken in Brazil. This scale was applied to 26 male patients (mean age = 12.7 ± 4.0 years) with Duchenne muscular dystrophy. Patients also answered questions of a Portuguese version of the Barthel index questionnaire, and had their right and left hand grip forces measured with a dynamometer. RESULTS: The mean total EK scale score was 8.1 ± 7.3 and the Barthel index 54.0 ± 26.2. The mean hand grip force was 12.7 ± 17.2 percent predicted for the right hand, and 14.6 ± 19.8 percent predicted for the left hand. The EK scale scores showed highly significant statistical correlations with age (r= 0.596, p= 0.0013), right hand grip force (r= -0.556, p= 0.0032), left hand grip force (r= -0.623, p=0.0007), and Barthel index (r= -0.928, p < 0.0001). CONCLUSION: This translated Portuguese version of the EK scale is an adequate tool to be used for Brazilian Duchenne muscular dystrophy patients.