Postural Torticollis and Early-Onset Scoliosis in Infants With SMA Identified Through Newborn Screening: Single...

In the era of disease modifying treatments (DMT), early-onset scoliosis may occur despite administration to infants with spinal muscular atrophy (SMA). We hypothesize that postural torticollis (Ptort), defined as tilt and/or rotation of the head to the same side due to an assumed asymmetry in cervical muscle strength, could be playing a role in early-onset scoliosis (EOS). The aim of this study was to assess the frequency of Ptort and EOS in infants with SMA.

Clinical data was collected retrospectively on infants with SMA identified by newborn screening (NBS) seen at a single institution, including SMN2 copy number; presence of torticollis, scoliosis, or both; and the date at which the patient received DMT. When available, spinal x-ray results and Cobb angles were recorded.

Twenty-three patients with 2-5 copies of SMN2 were included. Twenty (87%) were treated with DMT at a median age of 23.5 days of life (range 8-233 days). High prevalences of Ptort (52%) and EOS (30.5%) were reported. Four infants (17.4%) were noted to have Ptort preceding the development of EOS.

Early identification of Ptort and vigilance for the development of scoliosis are warranted even in treated infants. Further longitudinal studies are needed to evaluate the factors that are associated with this clinical observation.