Remarkable scientific breakthroughs have led to treatments for illnesses previously thought incurable. A striking example is the development of precision medicine approaches to correct genetically mediated neuromuscular diseases. In 2016, nusinersen, an antisense oligonucleotide, became the first approved treatment for spinal muscular atrophy (SMA), a pediatric neuromuscular disease that causes progressive muscle atrophy and weakness. The most common form of the disease, SMA type 1, leads to death by the age of 2 years and is the leading genetic cause of infant mortality. Spinal muscular atrophy types 2 and 3 have a less severe course, but affected children present with significant disability. The groundbreaking development of nusinersen is changing the natural history of SMA and is reshaping clinical practice, raising hopes that this landmark achievement will be followed by other targeted therapeutics for the many pediatric neuromuscular disorders that urgently need disease-modifying treatment options.
Pediatric physiatrists have long played a critical role in the management of neuromuscular diseases including SMA. The care of these patients is often centered around multidisciplinary clinics that provide a venue for coordinated care across multiple specialties. The first framework for SMA care, including rehabilitation recommendations, was established in 2007 when the International Conference on the Standard of Care for SMA published a consensus statement. These clinical guidelines have been widely used throughout the world for the last 10 years. With the approval of nusinersen in 2016 and the improvement in natural history, the SMA community recognized the need to update the guidelines that guide the care of people with SMA. To address this need, an international task force was created and their work resulted in the recent publication of two papers addressing different aspects of SMA diagnosis and management, focusing on rehabilitation and orthopedic, pulmonary, nutritional, and palliative care.1,2
GUIDELINE DEVELOPMENT METHODOLOGY
Spinal muscular atrophy experts and representatives from advocacy groups formed working groups and performed a detailed literature search. The Delphi method, a well-established technique that uses a systematic progression of rounds of voting, was used to reach consensus expert opinion. At least two rounds of Delphi were performed for each specific question. The following nine topics were included in this update: diagnosis and genetics; physical therapy and rehabilitation; orthopedic care, growth and bone health care; nutrition; pulmonary care; acute care in the hospital setting; other organ system involvement; medication; and ethics and palliative care.
ROLE OF REHABILITATION IN THE 2018 SMA GUIDELINES
A multidisciplinary approach is key in the management of SMA. Since the first SMA clinical guidelines were published in 2007, there has been increasing evidence that proactive rehabilitation may influence trajectories of progression. Regular sessions of physical therapy, daily stretching, and patient-centered prescription of bracing and equipment are encouraged.
The focus of clinical assessment is on the musculoskeletal system and related functional impairments. Physical examination should include assessment of strength, range of motion, relevant motor functional scales, and timed tests. Assessments include the evaluation of postural control, sitting tolerance, spine development and scoliosis, hip alignment and dislocation, chest deformities and limb contractures, mobility, endurance, balance, and falls as applicable. Rehabilitation goals vary based on disease subtype and severity. Goals include optimization of tolerance to various positions, prevention and treatment of contractures and scoliosis, and promotion of function and mobility.
Rehabilitation interventions should be tailored to SMA subtype and disease stage and include daily stretching and regular physical therapy; use of seating systems, postural, and positioning supports; cervical and trunk bracing for support and positioning; orthoses for upper and lower limbs for stretching, positioning, and promoting function and range of motion; mobile arm supports to assist upper extremity function; and supported standing and use of gait training devices and mobility systems as applicable. For milder phenotypes, exercise can promote function, endurance, and participation and may include swimming, cycling, hippotherapy, and wheelchair sports.
WHY IS THIS RELEVANT FOR PHYSIATRISTS?
Rehabilitation has been recognized as a critical aspect of SMA care. As new disease-modifying treatments emerge in the era of precision medicine and people with SMA live longer lives, the need for lifelong multidisciplinary rehabilitation will continue to grow.
1. Mercuri E, Finkel RS, Muntoni F, et al: Diagnosis and management of spinal muscular atrophy: part 1: recommendations for diagnosis, rehabilitation, orthopedic and nutritional care. Neuromuscul Disord
2. Finkel RS, Mercuri E, Meyer OH, et al: Diagnosis and management of spinal muscular atrophy: part 2: pulmonary and acute care; medications, supplements and immunizations; other organ systems; and ethics. Neuromuscul Disord