Relationship Between Central Hypotonia and Motor Development in Infants Attending a High-Risk Neonatal Neurology...

To study the relationship between central hypotonia and motor development, and to determine the relative contribution of nuchal, truncal, and appendicular hypotonia domains to motor development.

Appendicular, nuchal, and truncal tones of high-risk infants were assessed, as was their psychomotor developmental index (PDI). Infants with peripheral hypotonia were excluded.

We included 164 infants (mean age 9.6 ± 4 months), 36 with normal tone in all 3 domains and 128 with central hypotonia. Twenty-six of the latter had hypotonia in 1 domain and 102 had multiple combinations of 3 domains. Hypotonia domains were distributed as follows: truncal (n = 115), appendicular (n = 93), and nuchal (n = 70). Each domain was significantly associated with PDI scores (P < .001) but not with a later diagnosis of cerebral palsy. On linear regression, nuchal hypotonia had the strongest contribution to PDI scores (β = -0.6 [nuchal], -0.45 [appendicular], and -0.4 [truncal], P < .001).

Central hypotonia, especially nuchal tone, is associated with lowered motor development scores.