*Correspondence: gurgelgiannetti@gmail.com.
Abstract
Background: Spinal Muscular Atrophy (SMA) is the second most common neuromuscular disease in
childhood, with an estimated incidence of 1 in 11,000 live births. It leads to progressive
muscle weakness and consequently affects functional motor skills. In the last years,
therapies that modify the natural history of SMA have been developed, making the use
of instruments capable of objectively detecting the response to treatment and clinical
evolution of patients essential.
Objective: To translate and cross-culturally adapt to Portuguese-Brazil and determine the reliability
and validity of the HFMSE (Portuguese-Brazil). Investigate the relationship of motor
function with other measures, such as vital capacity (VC), peak cough flow (PCF),
muscle strength and joint amplitudes.
Methods: The translation process and cross-cultural adaptation followed international guidelines
recommendations. Two examiners assessed the participants for interrater reliability,
through the analysis of Kappa reliability agreement (k) and Intraclass Correlation
Coefficient (ICC). Validation consisted of applying the HFMSE scale and analyzing
its correlation with other relevant variables, such as muscle strength, respiratory
function and joint amplitudes.
Results: The HFMSE was successfully translated and cross- culturally adapted to Portuguese-Brazil.
Twenty-eight children/adults SMA type 2 and 3 were enrolled in the study (Type 2 =
14; Type 3 = 14). Fifteen (54%) were women and mean age of 20,6 ± 11, 8 years old.
The ICC for the total score showed very high reliability (ICC =1.00). A statistically
significant correlation was observed between the HFMSE and the VC measurement (p <
0.001), however there was no significance (p > 0.05) for the PCF measurement. Regarding
the presence of contractures, it was observed that hip and knee flexor contractures
are found in 92.9% of SMA type 2 participants and are directly correlated with the
score obtained in the HFMSE (p < 0.05). The muscle strength values obtained using
the manual dynamometer were significantly higher in SMA type 3 participants compared
to type 2 SMA participants. Through the results, it was possible to observe that the
knee extensors (2.4 ± 3.1 lbs) were the most compromised muscle group in both phenotypes.
Conclusion: The HFMSE (Portuguese-Brazil) proved to be valid and reliable for the evaluation
of patients with SMA type 2 and 3 in Brazil
