The nutritional management of patients with progressive neuromuscular diseases like Spinal Muscular Atrophy (SMA) is complex and is achieved optimally with an individualized approach from a multidisciplinary care team.1,2 Patients with SMA need nutritional monitoring at least annually with assessment of caloric intake and standard anthropomorphic measurements.3 In younger children, a dietician should evaluate diet and caloric intake every 3-6 months to ensure growth needs are being met.4 Nutritional status should be evaluated preoperatively for patients with SMA undergoing any surgical procedure.3,5
Malnutrition is not uncommon in children with SMA.6 Published studies report that patients with SMA typically have low to normal body weight with reduced lean body mass and increased body fat.7,8 Bone mineral density is related to ambulatory capability but is generally markedly reduced in most forms of SMA.7,9
Patients with the most severe forms of SMA (“non-sitters”) eventually will need enteral supplementation because they will be unable to take oral feeding safely due to bulbar involvement.8 The optimum diet that best serves non sitter patients with SMA is a matter of ongoing debate.4 A survey of caregivers in SMA type 1 found a range of formula types (elemental, semi-elemental, intact protein milk- and soy-based formulas) and feeding practices are being used in the community.8 There is no data showing a convincing superiority of amino acid formulas over intact protein formulas in SMA supplementation.4
Patients with later onset forms of SMA (“sitters”) may develop dysphagia but typically require supplemental, not total, enteral supplementation on a temporary or permanent basis. The SMA expert consortium does not endorse a specific formula for caloric and nutritional needs in sitters. SMA is a progressive disease, and sitters are particularly at risk of becoming overnourished and obese as their caloric needs are reduced as muscle mass and mobility diminish so regular dietary reassessment is critical to avoid complications of being overweight.10 Glucose intake and glycemic control are concerns in later onset forms of SMA because SMA may predispose to glucose intolerance11 that, together with obesity, could create risk of metabolic syndrome.4
The SMA expert consortium recommends an individualized approach to patient nutrition in SMA; they advise using the feeding regimen that meets nutritional needs (balancing growth and activity) and is best tolerated by the patient.2,4 Osteoporosis and poor bone health are common in all forms of SMA severity and should be managed more aggressively than current standards of care.9 The following micronutrient deficiencies have been associated with SMA and merit specific attention in nutrition assessment:
- Vitamins A, D, E, K4,7,10
- Alpha-linolenic acid7
- Linoleic fatty acid7
In acute illness or the perioperative setting, nutritional support should focus on:
- Providing adequate hydration4,5
- Maintenance of electrolytes within physiological ranges4,5
- Avoidance of prolonged fasting4,5
- Introduction of a meal with protein within 6 hours of acute decompensation or feeding intolerance4,5
1. Tilton AH, Miller MD, Khoshoo V. Nutrition and swallowing in pediatric neuromuscular patients. Seminars in pediatric neurology. 1998;5(2):106-115.
2. Wang CH, Finkel RS, Bertini ES, et al. Consensus statement for standard of care in spinal muscular atrophy. J Child Neurol. 2007;22(8):1027-1049.
3. Cuisset JM, Estournet B. Recommendations for the diagnosis and management of typical childhood spinal muscular atrophy. Revue neurologique. 2012;168(12):902-909.
4. 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. Neuromuscular disorders : NMD. 2018;28(2):103-115.
5. 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. Neuromuscular disorders : NMD. 2018;28(3):197-207.
6. Mehta NM, Newman H, Tarrant S, Graham RJ. Nutritional status and nutrient intake challenges in children with spinal muscular atrophy. Pediatr Neurol. 2016;57:80-83.
7. Moore GE, Lindenmayer AW, McConchie GA, Ryan MM, Davidson ZE. Describing nutrition in spinal muscular atrophy: A systematic review. Neuromuscular disorders : NMD. 2016;26(7):395-404.
8. Davis RH, Godshall BJ, Seffrood E, et al. Nutritional practices at a glance: Spinal muscular atrophy type i nutrition survey findings. J Child Neurol. 2014;29(11):1467-1472.
9. Wasserman HM, Hornung LN, Stenger PJ, et al. Low bone mineral density and fractures are highly prevalent in pediatric patients with spinal muscular atrophy regardless of disease severity. Neuromuscular disorders : NMD. 2017;27(4):331-337.
10. Poruk KE, Davis RH, Smart AL, et al. Observational study of caloric and nutrient intake, bone density, and body composition in infants and children with spinal muscular atrophy type i. Neuromuscular disorders : NMD. 2012;22(11):966-973.
11. Bowerman M, Swoboda KJ, Michalski JP, et al. Glucose metabolism and pancreatic defects in spinal muscular atrophy. Ann Neurol. 2012;72(2):256-268.