# Motor Outcome Measures in Pediatric Patients with Congenital Muscular Dystrophies: A Scoping Review
## 4 Discussion  
The scoping review method enabled an exhaustive literature search, a definition of the current level of knowledge, and the identification of gaps with respect to the current knowledge of motor function in pediatric patients with congenital muscular dystrophies. This study confirms that data published in the last 20 years on motor outcomes in patients with CMD are limited. Only 16 articles on this topic were found, of which 2 focused on COUVI-RD [8; 9], 1 on LMNA-RD [10], 2 on LAMA2-RD [11; 12], 2 on FCMD [14; 15], 2 on SEPN1-MD [15; 16], 1 on FKRP mutations [17], and 6 on different forms of CMD [18; 19; 20; 21; 22; 23]. As already reported by [PERSON] et al., the rarity of these diseases and the great phenotypic heterogeneity make large and comparable studies complex [5]. In this regard, attention is drawn to the pathologies analyzed in the selected articles. Despite the presence of numerous forms of CMD, most of the studies focused on the most represented and well-known forms (COUVI-RD, FCMD, LMNA-RD, LAMA2-RD, SEPN1-MD, FKRP). Only two articles mentioned other forms, although they are grouped in a single analysis category [19; 21]. Out of the 16 studies selected, 11 were cross-sectional studies. Only five studies were longitudinal and therefore analyzed the progression of motor function over time [11; 15; 17; 18; 22]. The durations of these longitudinal studies varied but were generally short and do not allow broad trend curves to be drawn. Two articles showed results from the same sample of patients to whom different inclusion criteria were applied [18; 22]. In fact, 44 of the 48 patients included in the study by [PERSON] et al. were included in the study by [PERSON] et al., i.e., all those with a diagnosis of LAMA2-RD or COL6-RD and with the completion of at least two MFM-32 evaluations one year apart. The cross-sectional studies provided information on the motor and functional aspects of the different forms of CMD, describing their common characteristics. However, they do not allow the evolution of the disease over time to be delineated. The age ranges of the patients varied. Only 8 out of 16 studies showed results from exclusively pediatric patients (0-18 years), although with different age ranges. The other 8 studies included samples of pediatric and adult patients, almost always without distinction in the analysis. Nevertheless, interesting preliminary data emerged regarding the progression of motor function in patients with LAMA2-RD, COL6-RD, SPN1-RM, and FKRP mutations. In patients with LAMA2-RD, an annual linear reduction of 6.6\({}^{\circ}\) for right elbow flexion and 3.1\({}^{\circ}\) for knee flexion was described in the article by [PERSON] et al. [11], and an annual reduction of 3.21\({}^{\circ}\) for left elbow extension in the article by [PERSON] et al. [18]. In the study by [PERSON] et al., a decrement of 2.60 points each year emerged on the MFM32 scale [18]. This decrement was confirmed by the study of [PERSON] et al., which showed a greater loss of score in the items related to axial and proximal function (\(-\)1.59 points per year) [22]. In patients with COL6-RD, an annual decrease of 4.01 points on the MFM32 scale was described in the study by [PERSON] et al. [18] and confirmed by the study of [PERSON] [22]. The domain in which there was the greatest loss of function was that of standing position and transfers (\(-\)1.99 points per year) [22]. In patients with SPN1-RM, an annual change of \(-\)0.55 points on the HFMS scale was estimated [15]. In patients with FKRP mutations, average annual decreases of 23.41 m at 6 MWT, 0.65 points on the MHFMS scale, 1.33 on the PEDI scale, and 0.55 on the PUL scale were reported [17]. Additional larger longitudinal studies differentiated by pediatric age and adulthood with planned follow-up would be recommended to study the course of the diseases over time, better understand the characteristics of the different forms, and trace natural history trajectories.