MFM is establishing itself as a functional scale in NMD, especially in infantile SMA

Tools intended to measure, as objectively as possible, motor strength and/or function in patients with neuromuscular diseases have proliferated in the last few years, especially in the context of innovative therapies appearing on the market. Motor function measure (MFM) is a scale that was developed by a Lyon-based team, and that has gradually established itself internationally. This scale consists of 32 items scored between 0 and 3, and explores three dimensions: D1 for the standing position and transfers; D2 for axial and proximal motor function; and D3 for distal motor function (maximum score = 96).

Two articles, which appeared in August and September 2020 respectively, illustrate the benefit of MFM in populations of patients affected by neuromuscular disease, including spinal muscular atrophy (SMA), a degenerative disease of the second motor neuron. In both cases, the data from the international MFM database were analysed in collaboration with Roche, which was also involved in the clinical development of risdiplam (Evrysdi®) in SMA. The first study related to 2 groups of patients with neuromuscular disease, one involving all types of patient in the paediatric age range (2-5 years), the other a broader age group (2 to 25 years) restricted to SMA patients who were not able to walk (type II and type III exclusively). The other study was similar in design and compiled data from patients with SMA who had participated in the trial for olesoxime, another drug molecule developed in SMA by Roche, the clinical development of which had been discontinued. The authors have confirmed the benefit of the complete version of the MFM (MFM32) for longitudinal studies and also its inherent properties (validity, reliability).

 

Validity and Reliability of the 32-Item Motor Function Measure in 2- to 5-Year-Olds with Neuromuscular Disorders and 2- to 25-Year-Olds with Spinal Muscular Atrophy. D Trundell, S Le Scouiller, K Gorni et al. Neurol Ther. 2020 (Août).

 

Assessment of the validity and reliability of the 32-item Motor Function Measure in individuals with Type 2 or non-ambulant Type 3 spinal muscular atrophy. D Trundell, S Le Scouiller, L Le Goff et al. PLoS One. 2020 (Sept). 15(9):e0238786.