Introduction
Spinal Muscular Atrophy is a rare neuromuscular disorder caused by autosomic recessive mutations in the Survival Motor Neuron 1 (SMN1) gene. According to age of onset and clinical severity, SMA is associated with different pediatric forms, among them type 1 and 2 are the most severe ones [1]. The weakness classically also involves the respiratory muscles with a typical diaphragmatic breathing pattern, most obvious in type 1 infants with subsequent need for mechanical ventilation support, recurrent hospitalization and, before treatment became available, premature exitus [2, 3].
The advent of new therapies increasing SMN protein either by gene replacement or incrementing SMN2 mRNA splicing, has produced a dramatic change in progression of the disease, improvement in survival, motor and respiratory function, more obvious in type 1 infants, who, until the advent of therapy, rarely survived beyond the 2nd year and never achieved independent sitting [4, 5, 6].
With increased survival it has become even more important to follow these patients over time. According to the SMA International Standard-of-Care (SoC), the assessments should be repeated every 3 to 6 months, involving a multidisciplinary team of specialists at tertiary centers for neuromuscular diseases, for routine in-personassessment and bed-side physical evaluations [2, 3].
Unfortunately, as a result of Covid-19 pandemic, the physical access to care, as well as our chance to guarantee the SoC, became more difficult since many tertiary centers had to limit routine in-person evaluation, focus resources and reduce the risk of infection. In order to address some of the difficulties faced by families to attend routine assessments, we first developed a “contactless ” patient video-monitoring platform [7] to assure a safe, privacy compliant and reliable access to specialists while providing, through questionnaires and tutorials, some essential care, including rehabilitation, that could not be otherwise guaranteed during the pandemic. While the platform proved to be extremely useful to replace some of the routine follow up assessments, SMA families were still very concerned about the difficulties experienced in getting physical examinations during acute events. Several parents reported that in the last few months “red flags” of respiratory infections, happened to go unnoticed or underestimated by themselves or local practitioners, who had little experience with neuromuscular diseases. In some cases that led to preventable complications which could have been avoided. In others, the absence of reliable assessment, parents rushed their children to emergency rooms even if this was often not necessary. And they were worried it may happen again.
We therefore decided to move beyond the video-monitoring solution to explore the feasibility of an innovative home-basedadvanced-telemedicine platform to perform challenging remote physical evaluation in type 1 and 2 SMA patients. Although there are many commercially available tools that could have been theoretically used to perform remote physical evaluation, there were however some concerns related to their applicability to type1 and 2 SMA patients. The concerns were related to the chest and trunk appearance of the SMA patients as most children present with kyphoscoliosis and thoracic asymmetry, ribs crowding, thoracic organ displacement (Fig. 1), that are often associated with pulmonary functional impairment and impaired airway clearance [8, 9, 10]. This has become particularly true in type 1 infants who now generally survive beyond the first year but despite the functional improvements, still have variable degree of trunk hypotonia and weakness causing kyphoscoliosis that has become one of the key features of the emerging post treatment new phenotypes.
Because of these concerns, we aimed to explore the feasibility of one of the advanced telemedicine platforms and explore its possible application into a clinical SMA setting.
More specifically, we wished to explore feasibility, accuracy, and experience with home-based virtual physical evaluation, especially focused on challenging lung auscultation, versus traditional bed-side exam in type 1 and 2 SMA children with different degrees of scoliosis and chest asymmetry. Our expectation is to find an innovative solution to guarantee safety and access to care, reduce infection exposure, logistic and economic burden for families and improve disease management, during Covid-19 and beyond.