The SMA Trust: the role of a disease-focused research charity in developing treatments for SMA

Revised Hammersmith Scale for spinal muscular atrophy: Inter and intra-rater reliability and agreement

The Revised Hammersmith Scale (RHS) for Spinal Muscular Atrophy (SMA) was designed as a psychometrically robust clinical outcome assessment to assess physical abilities of patients with type 2 and 3 SMA. The reliability properties of the RHS have not yet been reported. A prospective RHS reliability study was undertaken in a UK cohort of experienced neuromuscular paediatric Physiotherapists. Reliability testing was conducted via a virtual survey platform two weeks apart. Through the virtual platform participants scored videos of two RHS assessments, one of a child with SMA 2 and one of a child with SMA 3. Inter and intra-rater reliability was analysed using a type 3 Intraclass Correlation Coefficient (ICC). Intra-rater agreement was further analysed using Bland Altman (BA) Limits of Agreement (LOA) and plots. The acceptable inter and intra-rater variability was set as a change of ± 2 by the international team of expert physiotherapists who developed the RHS. Inter-rater agreement, n = 22 raters, type 3 ICC was 0.989 (95% CI 0.944 to 1.00), 97.7% of scores were within the acceptable limits of ± 2 points. Intra-rater agreement, n = 21 raters, type 3 ICC ranged from 0.922 to 1.0, with 97.6% of scores within the acceptable limits of ± 2 points. The mean SMA 2 intra-rater difference was -0.10 (-0.6 to 0.4), with lower LOA -2.24 and upper LOA +2.04. Intra-rater difference between tests for SMA 3 intra-rater difference was -0.05 (-0.6 to 0.5), with lower LOA -2.48 and upper LOA +2.38. Intra-rater scoring precision fell within BA agreement limits of ±2 points. The results demonstrate that the RHS is highly reliable when used by experienced UK physiotherapists, and variability of test scores regarding inter and intra-rater reliability was confirmed to lie within ±2 points.

New medicine for neuromuscular diseases: An evolving paradox for patient and family hopes and expectations

Recent developments in novel therapies for neuromuscular diseases offer parents new perspectives on their affected children's future. This article examines how the emergence of new therapies impacts the lives of parents of children with Duchenne muscular dystrophy or spinal muscular atrophy type 2, two genetic neuromuscular disorders characterized by progressive muscle degeneration. Aiming for a first-person perspective, fieldwork was conducted utilizing participant observation, semistructured interviews, and several internet sources. Six families with a total of 12 persons, all living in Denmark, were included in the interviews. Two types of parents were identified who were at opposite ends in dealing with the new therapies-the cure optimists and the cure pragmatists. Different hopes resulted in different narratives for their children's futures. The article raises questions about how and when children with chronic diseases should be involved in their parent's hopes for a cure and highlights the dilemmas facing health professionals working in the field of children with chronic diseases for which the prospects of a cure are improving. We conclude that health professionals must find a way to carefully balance guidance and information about experimental medicines, including the fact that experimental medicine sometimes fails, does not work as well as hoped for, or does not become available, with sustaining parental hopes for their children's future.

Current evidence for treatment with nusinersen for spinal muscular atrophy: a systematic review

Recent discovery of nusinersen, an antisense oligonucleotide drug, has provided encouragement for improving treatment of spinal muscular atrophy. No therapeutic options currently exist for this autosomal recessive motor neuron disorder. Nusinersen is developed for intrathecal use and binds to a specific sequence within the survival motor neuron 2 pre-messenger RNA, modifying the splicing process to promote expression of full-length survival motor neuron protein. We performed a MEDLINE and CENTRAL search to investigate the current evidence for treatment with nusinersen in patients with spinal muscular atrophy. Four papers were withheld, including two phase-3 randomized controlled trials, one phase-2 open-label clinical trial and one phase-1 open-label clinical trial. Outcome measures concerned improvement in motor function and milestones, as well as event-free survival and survival. Results of these trials are hopeful with significant and clinically meaningful improvement due to treatment with intrathecal nusinersen in patients with early- and later-onset spinal muscular atrophy, although this does not restore age-appropriate function. Intrathecal nusinersen has acceptable safety and tolerability. Further trials regarding long-term effects and safety aspects as well as trials including broader spinal muscular atrophy and age categories are required and ongoing.

The Role of AMPK in Neuromuscular Biology and Disease

AMP-activated protein kinase (AMPK) is a primary regulator of cellular metabolism. Recent studies have revealed that AMPK also mediates the maintenance and plasticity of α-motoneurons, the neuromuscular junction, and skeletal muscle. Furthermore, AMPK stimulation by either genetic, pharmacological, or physiological approaches elicits beneficial phenotypic remodeling in neuromuscular disorders (NMDs). Here, we review the role of AMPK as a governor of neuromuscular biology, and present evidence for AMPK as an effective molecular target for therapeutic pursuit in the context of the most prevalent NMDs, including Duchenne muscular dystrophy, spinal muscular atrophy, and myotonic dystrophy type 1. This information may be useful for engineering AMPK-targeted pharmacological- or lifestyle-based strategies to treat disorders of the neuromuscular system.

Advances in therapy for spinal muscular atrophy: promises and challenges

Spinal muscular atrophy (SMA) is a devastating motor neuron disease that predominantly affects children and represents the most common cause of hereditary infant mortality. The condition results from deleterious variants in SMN1, which lead to depletion of the survival motor neuron protein (SMN). Now, 20 years after the discovery of this genetic defect, a major milestone in SMA and motor neuron disease research has been reached with the approval of the first disease-modifying therapy for SMA by US and European authorities - the antisense oligonucleotide nusinersen. At the same time, promising data from early-stage clinical trials of SMN1 gene therapy have indicated that additional therapeutic options are likely to emerge for patients with SMA in the near future. However, the approval of nusinersen has generated a number of immediate and substantial medical, ethical and financial implications that have the potential to resonate beyond the specific treatment of SMA. Here, we provide an overview of the rapidly evolving therapeutic landscape for SMA, highlighting current achievements and future opportunities. We also discuss how these developments are providing important lessons for the emerging second generation of combinatorial ('SMN-plus') therapies that are likely to be required to generate robust treatments that are effective across a patient's lifespan.