Living with spinal muscular atrophy

Spinal muscular atrophy (SMA) is a genetic condition that causes progressive muscle weakness and wasting. Although living with SMA can pose many challenges in daily life, proper medical treatment, the use of adaptive equipment and support services, and maintaining a healthy lifestyle through diet and exercise can help people with the disorder engage in everyday activities and maximize their quality of life.

How does SMA type affect daily living?

There are five types of SMA, classified based on how the disease typically manifests and progresses:

• Type 0 SMA begins in the womb. It is almost always fatal in the first months of life.
• Type 1 SMA manifests within the first few months of life. Without treatment, most babies with this SMA type can’t lift their heads or sit without support, and typically die by age 2.
• Type 2 SMA begins in young children between 6 and 18 months of age. If untreated, children cannot stand or walk without support, and their lifespan is reduced.
• Type 3 SMA starts in childhood, after the age of 18 months. Individuals with this type usually can walk by the time symptoms appear, but without treatment, they may lose this ability as the disease progresses.
• Type 4 SMA manifests during adulthood. As the disease progresses, patients may experience muscle weakness and difficulty walking.

New treatments have dramatically changed the outlook for people with SMA. Many patients, including those with severe disease forms, are now living longer and experiencing a better quality of life than they used to.

SMA treatment options

The first disease-modifying therapy for SMA became widely available in the U.S. in 2016, with additional treatments approved in later years. While the specific mechanisms vary, all of the approved SMA treatment options target the underlying cause of the disease — deficits in the SMN protein.

Four SMA treatments have been approved in the U.S., all of which can be used for any disease type:

• Spinraza (nusinersen): First SMA treatment ever approved, administered via injection into the spine — called an intrathecal injection — every four months
• Evrysdi (risdiplam): Daily therapy approved for patients ages 2 months and older, with doses given orally or via a feeding tube
• Zolgensma (onasemnogene abeparvovec-xioi): Gene therapy for SMA approved to treat children through age 2, given via a one-time infusion into the bloodstream
• Itvisma (onasemnogene abeparvovec-brve): Gene therapy with the same active ingredient as Zolgensma, approved for adults and children ages 2 and older, given via a one-time intrathecal injection

These therapies aim to boost SMN production or activity, helping the protein fulfill its function of protecting motor neurons, the nerve cells that control voluntary movement. Preventing motor neurons from gradually dying off can slow or halt the progression of SMA symptoms.

However, these medications cannot revive motor neurons that have already died. For this reason, outcomes are almost always best when patients begin treatment as early as possible.

Pediatric SMA care

Newborn screening enables SMA to be diagnosed in infants before symptoms develop, allowing treatment to begin in the first weeks of life.

Some children who start treatment this early in life can have largely normal motor development, reaching milestones, such as crawling and walking, that would have been previously unattainable within typical timeframes.

Other children with SMA will eventually reach motor milestones, although at a slower pace than usual. Some children may not reach motor milestones, such as walking, even with treatment.

Adult SMA care

In adults with SMA, therapies can often help to stabilize motor function and prevent progressive decline. However, improvements in motor function are typically modest, if they occur at all. As with children, therapy outcomes vary depending on the stage of the disease when treatment begins, along with other factors that may affect individual responses to treatment, which remain incompletely understood.

Specialized equipment

Incorporating specialized equipment into daily routines can make day-to-day life with SMA easier and help improve health outcomes. People with SMA may use many types of adaptive equipment, including devices for mobility-related comfort and breathing support.

Mobility-related equipment

Some pieces of equipment may help patients overcome or adapt to the limitations that SMA muscle weakness has on their mobility:

• Adaptive strollers: These can help young children with SMA sit more comfortably, without being as heavy or difficult to transport as standard wheelchairs.
• Adaptive wheelchairs: They can help older patients get around independently, and may be manual or powered.
• Bath chairs and feeder seats: These can make bathing and eating easier for people with limited mobility, by minimizing repositioning.
• Braces and standers: These provide structural support to the body, helping build muscle strength or manage skeletal abnormalities.

Depending on the individual situation, mobility and support devices can improve function, independence, and comfort. They’re also key to preventing and managing skeletal problems, such as scoliosis in SMA. This abnormal curvature of the spine can affect movement and breathing.

Respiratory support

Weak chest muscles can make breathing more challenging for some people with SMA. Equipment that provides SMA respiratory support can help in various ways:

• Bi-level positive pressure (BiPAP) machines: A BiPAP machine can make it easier for a person to breathe by changing the pressure of air during inhalation and exhalation.
• Airway clearance devices: These include cough assist machines and high-frequency chest wall oscillation devices, which help clear mucus and other secretions so the airways stay clear.
• Pulse oximeters: This device measures oxygen levels in the blood, helping detect problems and guide care for people with breathing difficulties.
• Ventilators: These assisted breathing devices move air in and out of the lungs.

BiPAP machines are relatively noninvasive devices that can be worn as a mask over the nose and mouth or as a tube to the nose to facilitate breathing. Mechanical ventilators are more invasive, typically requiring the insertion of a tube into the airways. Ventilators may be needed when respiration is severely compromised, and patients can’t breathe sufficiently on their own.

Physical therapy and exercise

Engaging in regular exercise is essential for maintaining muscle health. For people with SMA, exercise can help improve motor function, boost flexibility and range of motion, maintain posture, prevent muscle contractures, and reduce stress. For most individuals with the genetic condition, regular exercise is key to maintaining a high quality of life.

Physical therapists and other specialists can help individuals with SMA develop a personalized exercise regimen that is both safe and suitable for patients and their caregivers. Experts often recommend finding playful and fun ways to incorporate physical activity into everyday routines.

Exercise and physical therapy options for SMA are varied:

• Aerobics: Such exercises increase heart rate to maintain cardiovascular and respiratory health. Examples include walking, swimming, dancing, boxing, rowing, and cycling.
• Resistance training: These exercises typically involve pushing against a force to build and preserve muscle strength and endurance. Examples are resistance bands and weight lifting.
• Water therapies: These guided exercises, completed in water, enable movement without putting pressure on the joints. They are usually done in a swimming pool with supervision.
• Stretching: Such exercises promote flexibility, mobility, and range of motion. Among them are yoga or other guided exercises done with a physical therapist.
• Upright activities: Exercises to strengthen muscles in the torso and core help to maintain posture and ease scoliosis. Examples include horseback riding or wheelchair games.
• Breathing exercises: These exercises strengthen the muscles that push air in and out of the lungs, and are usually guided by a specialist. They may include activities like blowing bubbles for children.

Diet

SMA diet and nutrition are key to living well with the lifelong disease. SMA can lead to both undernutrition and unintentional weight gain, both of which can negatively impact a person’s muscle health, overall health, and quality of life.

To date, there has been limited formal research on diet in SMA, and no single eating plan has been found to work for everyone with the disease. Nutritionists or dietitians can help patients formulate an individualized diet that provide a sufficient amount of healthy foods to give the body the energy and nutrients it needs. Healthy eating may include:

• lean proteins, like eggs, tofu, and low-fat dairy or soy-based dairy alternatives, to help maintain strength and support muscle health
• healthy fats, such as the omega-3 fatty acids found in avocados, olive oil, and fatty fish, to help fight inflammation and support nerve and joint health
• complex carbohydrates, including whole grains, fruits, and vegetables, for long-lasting energy
• nutrients that support bone health, like low-fat dairy products and leafy greens
• foods to support digestion, including fiber-rich fruits and vegetables, as well as probiotics, found in fermented foods like kefir, kombucha, and pickles
• plenty of water, to support digestion and help nutrients move through the body

Data have shown some disease-modifying treatments can help improve or stabilize nutritional status.

Fasting

People with SMA often have lower-than-normal muscle reserves, which means fasting or going a long time without food can have pronounced negative health effects, and should generally be avoided. However, in the absence of other health problems, children with SMA ages 1 or older usually do not need to be woken up at night to feed.

Weight gain

For SMA patients with limited mobility, it may be easy to gain excess weight because the body is not burning as much energy while moving around. At the same time, it can be challenging to engage in energy-intensive exercises to lose excess weight.

Such individuals may benefit from working with a specialist to optimize their energy intake — ensuring they’re getting the calories they need, but not more than their bodies will use.

Chewing and swallowing

SMA can cause weakness in the muscles of the jaw and throat, which may make it harder to chew and swallow food. Eating soft, easy-to-chew foods, or consuming foods in forms that are easy to swallow — like purees and smoothies — may make it easier for patients to get all the nutrients they need.

Babies with problems sucking and older patients with very limited swallowing abilities may benefit from using a feeding tube to ensure they can get adequate nutrition.

Gastroesophageal reflux disease and low-fat diet

Gastroesophageal reflux disease, or GERD, is a chronic condition in which stomach acid flows back into the esophagus, which is the tube that carries food from the mouth to the stomach. It often results in a sensation of heartburn.

GERD commonly affects people with SMA, particularly those with type 1 disease. Eating a low-fat diet — and especially avoiding fried or greasy foods — can help to reduce GERD symptoms. However, eating some fat is important for all people, especially young children. For this reason, patients and caregivers should talk to experts if they are considering switching to a low-fat diet.

Cutting out acidic foods like citrus or tomato sauce may also help ease GERD symptoms for some people.

Travel

Traveling can be intimidating for people with SMA and their families. Planning well in advance — and taking advantage of adaptive equipment and supportive services — can help make traveling with SMA less of a challenge.

For families affected by SMA, car travel may be easier in a vehicle with accommodations. For example, adapted cars may have storage for wheelchairs and other assistive devices. A car bed may be a safer option than a car seat for babies with SMA who have breathing problems.

Some older individuals with SMA are able to drive themselves, although they may require modified vehicles that are adapted to suit their needs.

When traveling by other methods, such as plane, bus, or train, accommodations and policies are often variable. Travelers may need to make special arrangements to transport wheelchairs and other adaptive equipment.

Many airlines and other travel services have specific policies in place to help people with special needs. By discussing their needs with service providers and making plans well in advance, people with SMA and their caregivers can help ensure everything goes as smoothly as possible at the time of travel.

Life expectancy and palliative care

Advances in care, particularly the availability of disease-modifying therapies, have dramatically changed the outlook for people with SMA, especially for those with more severe forms of the disease.

Historically, untreated babies with SMA type 1 did not survive past early toddlerhood. Now, such children who start treatment early in life can survive years into childhood, some with relatively normal motor development.

Because these treatments have only become available in recent years, scientists don’t yet know how they will affect SMA life expectancy in the long-term — right now, babies treated in the earliest clinical trials are approximately elementary school age.

Individuals with less severe SMA types 3 and 4 typically have normal life expectancy.

Many patients may benefit from palliative care for SMA. This branch of medicine aims to maximize comfort and improve quality of life for people with serious illnesses. While it sometimes includes planning for the end of life, it’s not the same thing as end-of-life or hospice care, and can be used regardless of disease type or stage.

It’s recommended that all people with SMA talk to their healthcare providers about developing a multidisciplinary palliative care plan to ensure their medical, social, emotional, and spiritual needs are met throughout their lives.