Processamento sensorial, nas idades de seis e 12 meses, em lactentes nascidos pré-termo e a termo: estudo prospectivo da resposta cortical e comportamento adaptativo à estimulação sensorial

Abstract

Although there is evidence of differences between preterm and full-term born infants in early sensory processing, with a high frequency of problems in preterm born infants, prospective research on preterm bitrth and adaptive sensory behavior during the first year of age is scarce and activity neural network underlying adaptive sensory behavior remains unknown. This observational, prospective, cohort, quantitative and analytical-descriptive study aimed to investigate cortical activity in response to sensory stimulation and adaptive sensory behavior at the ages of six and 12 months in preterm and full-term born infants. Participants were 43 preterm born infants (PT) and 36 at term born infants (T). At six and 12 months (corrected age for PT), we measured cortical activity in response to tactile stimulation with functional near infrared spectroscopy (fNIRS) and adaptive sensory behavior with Test of Sensory Functions in Infants (TSFI). Our cohort included 26 PT (gestational age = 31.0 ± 2.0 weeks; birth weight = 1,523.8 ± 499.2 grams) and 22 T (gestational age = 38.7 ± 1.1 weeks; weight at birth = 3,181.8 ± 314.4 grams). At both ages, we observed a total TSFI score lower in PT than in T (p <0.001) and, at 12 months, we observed scores in tactile (p = 0.03) and vestibular reactivity (p = 0.04) also smaller in PT. For the total sample, while the change observed in the total TSFI score from six to 12 months was positive (p <0.001), in tactile reactivity the change was negative (p = 0.02). Compared to six months, we demonstrated that male sex in PT may be related to lower results in tactile reactivity at 12 months, but further studies are needed to confirm this hypothesis. For the total sample at six months, we observed a cortical response contralateral to tactile stimulation in the primary sensorimotor cortex, and it was more frequent in T than in PT (p <0.01). For the total sample at 12 months, the cortical response contralateral to the tactile stimulation was observed in the primary sensorimotor cortex and premotor area, but while the response in the primary sensorimotor cortex was similar between T and PT, the response in the area pre-motor was more frequent in T (p <0.01). Still at 12 months for the total sample, we observed an ipsilateral response to tactile stimulation in the somatosensory association area, and it was more frequent in PT than in T (p = 0.02). Our main results indicate a negative impact of the preterm birth on early sensory processing. In infants born preterm, lower and variable results in tactile reactivity can be explained by a cortical response contralateral to tactile stimulation more immature and less homogeneous during the first year of life.