Machine learning approaches to evaluate infants' general movements in the writhing stage-a pilot study.

The goals of this study are to describe machine learning techniques employing computer-vision movement algorithms to automatically evaluate infants' general movements (GMs) in the writhing stage. This is a retrospective study of infants admitted 07/2019 to 11/2021 to a level IV neonatal intensive care unit (NICU). Infant GMs, classified by certified expert, were analyzed in two-steps (1) determination of anatomic key point location using a NICU-trained pose estimation model [accuracy determined using object key point similarity (OKS)]; (2) development of a preliminary movement model to distinguish normal versus cramped-synchronized (CS) GMs using cosine similarity and autocorrelation of major joints. GMs were analyzed using 85 videos from 74 infants; gestational age at birth 28.9 ± 4.1 weeks and postmenstrual age (PMA) at time of video 35.9 ± 4.6 weeks The NICU-trained pose estimation model was more accurate (0.91 ± 0.008 OKS) than a generic model (0.83 ± 0.032 OKS, p < 0.001). Autocorrelation values in the lower limbs were significantly different between normal (5 videos) and CS GMs (5 videos, p < 0.05). These data indicate that automated pose estimation of anatomical key points is feasible in NICU patients and that a NICU-trained model can distinguish between normal and CS GMs. These preliminary data indicate that machine learning techniques may represent a promising tool for earlier CP risk assessment in the writhing stage and prior to hospital discharge.

Hyperacute muscle weakness in an unusual coexistence of antisignal recognition particle and anti-Mi-2 antibodies.

Idiopathic inflammatory myopathies are a heterogeneous group of systemic diseases characterised by variable phenotypes of chronic progressive muscle weakness. Myositis-specific antibodies (MSAs) include antibodies to cytoplasmic signal recognition particle (SRP) and various tRNA synthetases as well as the nuclear helicase protein Mi-2. These antibodies are typically found only in a fraction of true myositis cases and they tend to be mutually exclusive. Few cases of coexistence of two MSAs in the same patient have been reported and these cases all involve an antisynthetase antibody coexisting with either anti-SRP or anti-Mi-2 antibody. Peculiar clinical manifestations may be associated with different combinations of MSAs but the rarity of these cases makes their characterisation difficult. We report the first ever case of anti-SRP and anti-Mi-2 copositive polymyositis in a 19-year-old boy who presented with a week history of profound muscle weakness that attained its peak within 24 hours of onset.