The effect of long term ventilatory support on hemodynamics in children with spinal muscle atrophy (SMA) type II

Outcomes of Long-term Non-invasive Ventilation Use in Children with Neuromuscular Disease: Systematic Review and Meta-analysis

OBJECTIVE

To determine whether children with neuromuscular disorders using long-term non-invasive ventilation, continuous or bilevel positive airway pressure, have improved health outcomes compared to alternative treatment strategies.

DATA SOURCES

This systematic review is an extension of a scoping review. The search strategy used Medical Subject Headings (MeSH) and free-text terms for "child" and "non-invasive ventilation." Studies of humans from 1990 onward were searched in MEDLINE (Ovid), Embase (Ovid), CINAHL (Ebsco), Cochrane Library (Wiley), and PubMed. The results were reviewed for articles reporting on neuromuscular disorders and health outcomes including mortality, hospitalization, quality of life, lung function, sleep study parameters, and healthcare costs.

DATA EXTRACTION

Extracted data included study design, study duration, sample size, age, type of non-invasive ventilation, follow-up period, primary disease, and primary and secondary outcome measures. Studies were grouped by primary disease into 3 groups: spinal muscular atrophy, Duchenne muscular dystrophy, and other/multiple neuromuscular diseases.

DATA SYNTHESIS

A total of 50 articles including 1412 children across 36 different neuromuscular disorders are included in the review. Mortality is lower for children using long-term non-invasive ventilation compared to supportive care across all neuromuscular disease types. Overall, mortality does not differ when comparing the use of non-invasive ventilation to invasive mechanical ventilation though heterogeneity suggests that mortality with non-invasive ventilation is higher for spinal muscular atropy type-1 and lower for other/multiple neuromuscular diseases. The impact of long-term non-invasive ventilation on hospitalization rate differed by neuromuscular disease type with lower rates compared to invasive mechanical ventilation but higher rates compared to invasive mechanical ventilation use for spinal muscular atrophy type 1, and lower rates compared to before NIV for other/multiple neuromuscular diseases. Overall, lung function was unaltered and sleep study parameters were improved from baseline by long-term non-invasive ventilation use. There are few data to assess the impact of long-term non-invasive ventilation use on quality of life and healthcare costs.

CONCLUSION

Long-term non-invasive ventilation for children provides benefit for mortality, hospitalizations, and sleep study parameters for some sub-groups of children with neuromuscular disorders. High risk of bias and low study quality preclude strong conclusions.

Spinal Muscular Atrophy

Spinal muscular atrophy is an autosomal-recessive disorder characterized by degeneration of motor neurons in the spinal cord and caused by mutations in the survival motor neuron 1 gene, SMN1. The severity of SMA is variable. The SMN2 gene produces a fraction of the SMN messenger RNA (mRNA) transcript produced by the SMN1 gene. There is an inverse correlation between SMN2 gene copy number and clinical severity. Clinical management focuses on multidisciplinary care. Preclinical models of SMA have led to an explosion of SMA clinical trials that hold great promise of effective therapy in the future.

Spinal muscular atrophies

Spinal muscular atrophies (SMAs) are hereditary degenerative disorders of lower motor neurons associated with progressive muscle weakness and atrophy. Proximal 5q SMA is caused by decreased levels of the survival of motor neuron (SMN) protein and is the most common genetic cause of infant mortality. Its inheritance pattern is autosomal recessive, resulting from mutations involving the SMN1 gene on chromosome 5q13. Unlike other autosomal recessive diseases, the SMN gene has a unique structure (an inverted duplication) that presents potential therapeutic targets. Although there is currently no effective treatment of SMA, the field of translational research in this disorder is active and clinical trials are ongoing. Advances in the multidisciplinary supportive care of children with SMA also offer hope for improved life expectancy and quality of life.

Childhood spinal muscular atrophy: controversies and challenges

Spinal muscular atrophy is an autosomal recessive disorder characterised by degeneration of motor neurons in the spinal cord and is caused by mutations of the survival of motor neuron 1 gene SMN1. The severity of spinal muscular atrophy is highly variable and no cure is available at present. Consensus has been reached on several aspects of care, the availability of which can have a substantial effect on prognosis, but controversies remain. The development of standards of care for children with the disorder and the identification of promising treatment strategies have changed the natural history of spinal muscular atrophy, and the prospects are good for further improvements in function, quality of life, and survival. A long-term benefit for patients will be the development of effective interventions (such as antisense oligonucleotides), some of which are in clinical trials. The need to be prepared for clinical trials has been the impetus for a remarkable and unprecedented cooperation between clinicians, scientists, industry, government, and volunteer organisations on an international scale.

Spinal muscular atrophy: a clinical and research update

Spinal muscular atrophy, a hereditary degenerative disorder of lower motor neurons associated with progressive muscle weakness and atrophy, is the most common genetic cause of infant mortality. It is caused by decreased levels of the "survival of motor neuron" (SMN) protein. Its inheritance pattern is autosomal recessive, resulting from mutations involving the SMN1 gene on chromosome 5q13. However, unlike many other autosomal recessive diseases, the SMN gene involves a unique structure (an inverted duplication) that presents potential therapeutic targets. Although no effective treatment for spinal muscular atrophy exists, the field of translational research in spinal muscular atrophy is active, and clinical trials are ongoing. Advances in the multidisciplinary supportive care of children with spinal muscular atrophy also offer hope for improved life expectancy and quality of life.