Management of Swallowing Problems Should be Tailored for Each Child With SMA Type 1, Small Study Suggests

Because babies with type 1 spinal muscular atrophy (SMA) develop serious swallowing problems at different ages, the decision to switch from oral to tube feeding should be tailored for each child, researchers in South Korea suggest.

Their study, “Trajectory of change in the swallowing status in spinal muscular atrophy type I,” was published in the International Journal of Pediatric Otorhinolaryngology.

Symptoms of SMA type 1, the most common and one of the most severe forms of the disease, begin immediately after birth or in the first six months of life.

Early on, babies with SMA type 1 have trouble sucking and swallowing, which puts them at greater risk of inhaling food or liquids, and developing aspiration pneumonia, a lung infection caused by the entry of food or liquids into the lungs.

A high incidence of acid reflux (when stomach acids, or food and fluids back up from the stomach into the esophagus) also has been reported.

To understand the progression of swallowing problems and gather insights that could help improve care, a team of researchers from South Korea reviewed data from 11 children with SMA type 1 from birth to age 2.

The team evaluated how each child scored on the Neuromuscular Disease Swallowing Status Scale (NdSSS), which measures feeding difficulties for people with neuromuscular diseases, and is rated by a trained occupational therapist.

They also analyzed data from videofluoroscopic swallow studies (VFSS) — a  test in which a patient consumes different foods and drinks that have been mixed with barium; the barium makes the food and drinks show up on an X-ray so that doctors can see the different phases of swallowing while it’s happening.

The test allows doctors to see the parts of the mouth and throat that are not working properly, and if food is going into the airways instead of the stomach (aspiration).

All of the children in the study had oral problems as a result of weak facial and chewing muscles, including limited mouth opening, drooling, and difficulty in chewing solid food. The extent of deterioration in their swallowing function varied before they were a year old.

Serious problems in swallowing began when they were around six months old, as measured by the NdSSS scale. By that time, they stopped breastfeeding or bottle-feeding, and were started on tube feeding (either a nasogastric or gastrostomy tube) due to poor oral intake, recurrent pneumonia, and aspiration problems.

The babies switched from oral feeding to tube feeding at varying ages, ranging from 5 to 12 months.

Videofluoroscopy results were available for five patients, four of whom had evidence of aspiration of oral contents, such as bottled milk or curd-type yogurt. Two babies experienced aspiration at 3 and 4 months of age, while one patient stayed on oral feeding for up to 12 months without signs of aspiration.

Because the age at which these babies experienced swallowing difficulties varied significantly, “rather than switching to tube feeding at a specific time, an individualized approach is recommended to optimize the care of patients with SMA type 1,” the researchers wrote.

The researchers recommended two different strategies for deciding when or if to start tube feeding.

“First, if oral feeding alone cannot provide sufficient nutrition because of decreased oral and pharyngeal function, it might be advisable to start tube feeding promptly without a VFSS, regardless of maintaining oral feeding,” the researchers said. Five patients in the study were switched to tube feeding using this strategy.

“The second strategy (…) is to evaluate whether oral feeding can be safely continued with regular VFSS even during the full oral feeding period.”

VFSS tests can also be used to determine the proper texture and amount of food needed so that children can experience tasting, even when tube feeding is regularly used.