Oral and Swallowing Abilities Tool (OrSAT) for Type 1 SMA Patients: Development of a New Module

Abstract

We describe the development of a new tool specifically designed to record oral abilities, swallowing and, more generally, feeding in young type 1 SMA patients, to be used during the first 24 months of life.The tool is composed by a checklist and a separate section summarizing the functional abilities into levels of feeding/swallowing impairment. The checklist includes 12 questions assessing aspects thought to be clinically meaningful for a type 1 SMA population and developmentally appropriate for infants during the first months of life. Each item is graded with a score of 0 or 1, depending on the child's ability to perform the activity. As some items are age-dependent, the number of items to be used, and therefore the maximum score, changes with increasing age. The levels of feeding/swallowing impairment include four levels that can be identified using easily identifiable clinical criteria.In an attempt to validate the tool in an untreated population we applied it to 24 type 1 SMA patients (age range: 2.3-24.1 months, mean: 10.8) in whom the same information collected by the new tool had been previously recorded using a less-structured format.When patients were classified in three groups according to the Dubowitz decimal classification, there was a significant difference both at baseline and at follow-up (p < 0.001). The items assessing fatigue during the nursing sessions were the most frequently impaired even in infants who did not have any other obvious clinical sign of swallowing difficulties.

Keywords: Spinal muscular atrophy; dysphagia; oral motor function; swallowing; type 1 SMA infants.

Fig. 1

Individual details of the scores in the different subgroups according to severity highlighted by age range (0–5; 6–9; 10–24 months). The shaded areas corresponds to the maximum total score of the tool corresponding to what is expected in neurotypical infants.

Fig. 2

Change in levels of impairment in the study cohort subdivided by SMA 1 decimal classification and visits: Each symbol corresponds to a single patient at each given age (open dot ○: no impairment; barred dot ø: mild impairment; grey dot •: moderate impairment; full dot •: severe impairment; the symbol –was used when an evaluation was not performed).

Fig. 3

Correlation between total OrSAT checklist scores and age in different subgroups subdivided according to the OrSAT level of impairment. (○: no impairment; barred dot ø: mild impairment; grey dot \color grey•: moderate impairment; full dot •: severe impairment. Each symbol corresponds to a single patient. The shaded areas identify the maximum total OrSAT checklist score expected in typically developing infants at different ages (grey 0–5 months; Pink 6–9 months green: 10–24 months).