Evolving Dieting Strategies Address New Challenges in SMA Care

The treatment landscape for spinal muscular atrophy (SMA) has changed substantially with the emergence of disease-modifying therapies (DMTs), newborn screening, and earlier intervention. As more children are treated before significant motor neuron loss occurs, clinicians are increasingly focused not only on survival and disease stabilization, but also on maximizing strength, function, growth, and quality of life.

Nutrition is an important part of that evolving multidisciplinary approach. For children with SMA, nutritional management can be complicated by reduced energy requirements, swallowing dysfunction, gastrointestinal issues, and the risk of both inadequate nutrition and excess weight gain. At the same time, the emergence of effective DMTs has created new questions about how nutritional goals should be defined for children who are now achieving functional outcomes that were previously uncommon.

To explore the changing role of nutrition in SMA care, NeurologyLive® spoke with Stacey Tarrant, RD, LDN, a dietitian who has worked with patients in the Boston Children’s Hospital multidisciplinary SMA clinic for 18 years. She discussed how the arrival of DMTs has changed nutritional priorities, the role of individualized dietary management within the broader SMA care team, and the need for better evidence to establish optimal growth and body-composition targets for children treated early in the disease course.

NeurologyLive: From your perspective as dietitian, how has your understanding of SMA's impact on patients and families evolved over your career?

Tarrant, RD, LDN: As the dietitian for Boston Children’s multidisciplinary SMA clinic, I have witnessed the shift from families coping with an untreatable degenerative disease to having treatments that offer real hope for their child’s future. Before DMTs became available, nutrition was often one of the main areas where families felt they could meaningfully improve their child’s comfort and quality of life.

Many connected through social media to share tube-feeding recipes and strategies aimed at reducing gastrointestinal discomfort, as well as supplements they believed were helpful. For children who could eat safely by mouth, maintaining enjoyment of food was often the priority, with less emphasis on nutritional quality.

As DMTs have changed the clinical course of SMA - helping preserve swallowing and improving gastrointestinal health - nutrition care has also evolved, with greater emphasis on optimizing dietary quality to promote strength and muscle gain.

What does a typical care journey look like for a patient with SMA from your vantage point as dietitian, and where does your role fit into the broader care team?

From a nutrition perspective, there is no “typical” care journey for a patient with SMA, especially now. Nutrition needs vary based on the DMT(s) a patient receives, when treatment began, how long they have been treated, and their individual response.

My role on the care team is to provide individualized nutrition care to maximize strength, function, and quality of life. This includes helping patients achieve appropriate growth and weight while avoiding both undernutrition and excess weight gain, which can worsen fatigue and weakness. Because patients with SMA generally have lower calorie needs, calorie quality matters. I emphasize nutrient-dense, minimally processed foods whenever possible.

Despite DMT treatment, some of our patients still have poor swallow function and require tube feeding to either supplement their oral intake or as their sole source of nutrition. For these patients, I recommend commercial formulas made of real, blended foods to optimize gastrointestinal health.

What has been the most meaningful shift you've seen in SMA treatment or management since the approval of DMTs?

The discovery and approval of DMTs for SMA - followed by the addition of SMA to newborn screening panels and the opportunity for pre-symptomatic treatment - has been the most meaningful advancement in pediatric disease management that I have witnessed in my career. I now care for children who, in the past, would have had no muscle movement, required mechanical ventilation, and depended entirely on tube feeding, but who are now able to walk, breathe independently, and eat by mouth.

As clinicians, this has shifted our focus from managing symptoms without expecting meaningful improvement to treating with the goal of increasing strength, function, and quality of life. Many children are now achieving outcomes that would not have been possible 10 years ago, and this shift has been miraculous!

What's one misconception about SMA care within your specialty or the field broadly that you'd like clinicians to understand better?

One misconception I wish other clinicians understood is that nutrition care is a long-term relationship, not a quick fix. Food is deeply personal, and eating is tied to comfort, family routines, culture, and quality of life. Motivating people to change what they eat is a process that requires patience, trust, and time. Success often happens in baby steps.

If a patient or family can make and sustain even one positive change, this is real progress. I have also found, especially in working with children who I have known from pre-school age to young adulthood, that the nutrition messages you give early on may not take hold right away, but sometimes those messages resurface years later, when the patient or family is ready, and that can be incredibly rewarding to see.

Looking ahead, what unmet need or open question in SMA care are you most focused on right now?

One question I am especially focused on is understanding the optimal growth target for children with SMA who are treated pre-symptomatically with DMTs. Clinicians have observed that excess weight may limit gains in strength and function, while inadequate caloric and nutrient intake may also restrict progress.

An important question is whether there is an optimal BMI percentile for age or measurement of body composition that best supports strength and functional gains in these treated children who are actively participating in physical therapy. Answering this question with stronger scientific evidence would help clinicians provide more precise nutrition guidance and give families clearer, evidence-based goals to help maximize the benefits of treatment.

Transcript edited for clarity.