Application of the neonatal ‘floppy module’ to older infants: can it be used for differential diagnosis?

In this study we applied the ‘floppy module’, originally developed for newborns with hypotonia, to older infants in order to establish the range of findings in both low-risk infants and in those with hypotonia due to different etiologies. Data were collected from 413 assessments obtained in 159 low-risk infants assessed at different ages between the age of 3 and 24 months. The distribution of findings in the low-risk infants was similar to the data previously obtained in low-risk newborns, with all assessments having optimal findings (column 3) on all items. The only item with a small number of findings outside column 3 was tendon reflexes. The module was also applied to a cohort of 57 infants with hypotonia older than 3 months in order to identify individual items that may be useful in differential diagnosis. Items assessing antigravity movements were the most sensitive to identify neuromuscular disorders. Dysmorphic features and other organ involvement were most suggestive of genetic disorder, while seizures were a reliable indicator of CNS involvement. Conclusion: Our findings suggest that the neonatal floppy module can be reliably administered also in infants from the age of 3 months. The pilot application of the module in infants with hypotonia from the age of 3 months also suggested that the module could be used to help the clinician in the differential diagnosis of infants with hypotonia. (Table presented.)