REGISTRIES AND CARE OF NEUROMUSCULAR DISORDERS: P.285Validation of the Brazilian Portuguese version of the motor function measure - short form (MFM-20) for neuromuscular diseases in children from two to seven years old

Abstract

Neuromuscular disorders (NMD) include a large number of conditions involving muscle weakness. There is a lack of tools to assess motor function in young children with NMD. The Motor Function Measure (MFM-32), validated in Brazil as MFM-P, monitors the severity and progression of motor function in patients with NMD, from six to sixty years old. As this version was not validated in children under six years of age, the authors of the original version, from Pediatric Reeducation Service L'Escale (France), developed the Motor Function Measure - Short Form (MFM-20), designed for children from two to seven years old. The aim of this study was to test the reliability and validity of MFM-20 in Brazilian Portuguese. The translation of MFM-20 was performed by the same researchers that translated MFM-32 in Brazil. After a pretest in a sample of five subjects, the translated version was applied with twenty-six children with NMD. To verify the inter-rater reliability, the Wilcoxon Test compared the scores given within one-week interval and the Student's Test compared the scores given by two physical therapists at the first day. To verify the converging construct validity between MFM-20 and Hammersmith Motor Functional Scale (HMFH), Barthel's Index (BI) and Vignos and Brooke Scale (VBS), as well as the discriminating construct validity between MFM-20 and the Medical Research Council Scale (muscular strength), Pearson correlation tests were applied. Twenty six patients with mean age 4.6 ± 1.5 years old were included in this study, with the following clinical diagnosis: Duchenne muscular dystrophy (n=9), congenital muscular dystrophy (n=5), congenital myopathy (n=6) and type 2 spinal muscular atrophy (n= 6). The reliability analysis demonstrated good reproducibility for intra-rater on the first day (35.8±8.8) and after one week (37.0±9.0); p= 0,050, and good inter-rater reproducibility (examiner 1: 35.8±8.8 and examiner 2: 35.1±9.2). The converging validity analysis demonstrated good correlation between MFM-20 and HMFS, VBS and BI, with correlation coefficients: 0.907, -0.918 and 0.797, respectively. The discriminating validity analysis demostrated positive correlation between MFM-20 and Medical Research Council, with a correlation coefficient 0.873. The Brazilian Portuguese version of MFM-20 showed validity, representing advances for patients in Brazilian's centers.