Spinal Muscular Atrophy: Gastrointestinal Access

Spinal Muscular Atrophy: Gastrointestinal Access

Spinal Muscular Atrophy (SMA) is a degenerative neuromuscular disease that, in its most severe manifestations (i.e., SMA types 0 and 1), will progress to bulbar paralysis.1 Some clinicians suggest that gastroesophageal reflux and aspiration risk are universal features in SMA type 1. 2,3 

A current consensus statement from a consortium of SMA experts explains that “[s]afe swallowing is one of the most important aspects to consider” for the most severely affected patients with SMA.4 If a patient with SMA fails a swallow study or exhibits growth failure, the expert panel recommends placement of a temporary nasogastric or nasojejunal tube until a long-term gastrostomy tube can be placed.4 Nasogastric or gastrostomy feeding can provide overnight supplementation to oral feeding and anticipate inevitable bulbar paralysis and loss of safe and productive oral feeding.5 Though it is not a universal recommendation, gastrostomy tube placement can be performed with a Nissen fundoplication to address reflux concerns.4 With appropriate pre- and post-surgical management, these procedures are generally well tolerated in patients with SMA.3,6 The most debilitated SMA type 0 and 1 patients with respiratory compromise may pose a higher anesthesia risk, and thus the benefits of a long-term feeding portal would need to be weighed against the risk of surgical complications and death.5

The placement of a gastrostomy tube in patients with severe, fatal forms of SMA was not always as common a practice, but more proactive interventions such as gastrostomy placement appear to have prolonged survival in SMA.7,8 Gastrostomy placement appears to significantly increase weight gain, improve symptomatic reflux, reduce incidences of aspiration pneumonia and reduce risk of death.9

There are ethical concerns about artificial prolongation of life using invasive ventilation at the cost of quality of life in SMA,10 but there does not appear to be as much controversy with tube feeding. According to a survey of type 1 SMA patients, 43 out of 44 utilized a feeding tube for essential nutrition. Experts advise that the decision to place a gastrostomy tube be the outcome a dialogue between a multidisciplinary care team and the family.5 There is no data to suggest that gastrostomy feeding is superior to nasogastric feeding.5

Even less severe forms of SMA (i.e., types 2 and 3) can exhibit bulbar dysfunction.11,12 Estimates range as high as 44% of type 2 and 3 SMA patients report swallowing difficulties.9 For these patients, less invasive treatment strategies such as postural repositioning4 or strengthening exercises for the neck may ameliorate swallowing dysfunction.11 Underfeeding and overfeeding may occur in approximately 30-40% of patients with SMA types 2 and 3,13,14 leading some to suggest that an individualized approach with regular re-evaluation to address nutritional needs is best in these patient populations.4,13

References

1. Shababi M, Lorson CL, Rudnik-Schoneborn SS. Spinal muscular atrophy: a motor neuron disorder or a multi-organ disease? J Anat. 2014;224(1):15-28.

2. Iannaccone ST. Spinal muscular atrophy. Seminars in neurology. 1998;18(1):19-26.

3. Durkin ET, Schroth MK, Helin M, Shaaban AF. Early laparoscopic fundoplication and gastrostomy in infants with spinal muscular atrophy type I. J Pediatr Surg. 2008;43(11):2031-2037.

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. Roper H, Quinlivan R. Implementation of “the consensus statement for the standard of care in spinal muscular atrophy” when applied to infants with severe type 1 SMA in the UK. Archives of Disease in Childhood. 2010;95(10):845-849.

6. Birnkrant DJ, Pope JF, Martin JE, Repucci AH, Eiben RM. Treatment of type I spinal muscular atrophy with noninvasive ventilation and gastrostomy feeding. Pediatr Neurol. 1998;18(5):407-410.

7. Oskoui M, Levy G, Garland CJ, et al. The changing natural history of spinal muscular atrophy type 1. Neurology. 2007;69(20):1931-1936.

8. Yuan N, Wang CH, Trela A, Albanese CT. Laparoscopic Nissen fundoplication during gastrostomy tube placement and noninvasive ventilation may improve survival in type I and severe type II spinal muscular atrophy. J Child Neurol. 2007;22(6):727-731.

9. 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.

10. Smith M. Long-term ventilation in spinal muscular atrophy: the price of progress. Developmental medicine and child neurology. 2017;59(8):774.

11. Cha TH, Oh DW, Shim JH. Noninvasive treatment strategy for swallowing problems related to prolonged nonoral feeding in spinal muscular atrophy type II. Dysphagia. 2010;25(3):261-264.

12. van Bruggen HW, Wadman RI, Bronkhorst EM, et al. Mandibular dysfunction as a reflection of bulbar involvement in SMA type 2 and 3. Neurology. 2016;86(6):552-559.

13. Martinez EE, Quinn N, Arouchon K, et al. Comprehensive nutritional and metabolic assessment in patients with spinal muscular atrophy: Opportunity for an individualized approach. Neuromuscular disorders : NMD. 2018;28(6):512-519.

14. 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.