The purpose of the study was to identify and compare characteristics of preterm infants' pulse rate, respiratory rate, stress related behavior and self comforting behavior in two situations: (1) the infant receiving routine nursing care in the environment of a neonatal intensive care nursery, and (2) the infant in the same environment after experiencing a gentle back massage. Specifically, the research question for this study was: what patterns of pulse rate, respiratory rate and behavior, are associated with massage? Preterm infants between 33 and 36 weeks gestational age were observed for a baseline period of 50 minutes, given a 10 minute back massage, and observed for an additional 50 minutes. Exploratory data analysis revealed changes in the pulse rate, and in the frequencies of stress related and self comforting behaviors after massage that were associated with gestational age. Younger infants displayed a decline in pulse rate and an increase in respiratory rate after massage when compared to baseline observations, whereas older infants showed an increase in pulse rate immediately following massage. Stress related behavior declined during the first 10 minutes after massage in all age groups. Most preterm infants in this sample did not manifest any stress related behavior for several minutes after the massage. The frequency of self comforting behaviors increased after infants experienced a massage. Behavioral patterns were coupled with physiological variables; the frequency of self comforting behaviors was reflected in the pattern of respiratory rate whereas the frequency of stress related behaviors was more closely coupled with pulse rate. As infants became more aroused, they used a greater variety of behaviors. The behavioral reportoire also increased with gestational age. Content analysis demonstrated that infants spent more time in quiet sleep after having a massage than before massage. There were more frequent changes between active and quiet sleep before massage than afterward among infants who were treated concurrently with ultraviolet light. There was a trend for infants of all ages to take less time to console themselves after having a massage than before. None of these observed differences was statistically significant. Rotational movements were noted among more mature infants and were associated with quiet sleep. Infant behaviors showed a general decrease in the amplitude of movement over time. Several infants appeared alert, opening their eyes and looking around after having a massage. In general, preterm infants in this sample manifested changes in arousal and in activity which were observed in the differences in their behavior and vital signs after having a massage.

The purpose of this study was to assess if preterm infants receiving an intervention of intermittent human tactile contact would demonstrate clinical improvement over infants who did not receive the intervention. A quasi-experimental design was used with 26 infants between 28 and 32 weeks gestation. Hands were placed on the infants' heads and lower backs for a total of 36 minutes of tactile contact a day for 10 days. Findings indicated a significant gain in mean body weight for both groups between Day 0 and Day 10. Also, there was a significant decrease in mean hematocrit in the control group between Day 0 and Day 10. On Day 10, experimental infants had a significantly higher mean number of apneic and bradycardic episodes than control infants. There were no significant mean differences between the groups for body weight, body temperature stability, oxygen variance, or hematocrit. Data suggest that gentle human touch may be correlated with desireable outcomes. Further research is necessary.

D.Cur. / The feeding of low birth weight babies remains a challenge. Mother's milk is deficient in protein, calcium, magnesium and phosphate. These elements need to be supplemented in order for the low birth weight baby to grow under optimal conditions. The objective of the study was to compare the growth of the low birth weight baby, who was only fed mothers milk, to the low birth weight babay who was fed mother's milk with a commercial fortifier, using mass, lenght and head circumference as a guide. The literature study has shown that there are different methods which can be used to compliment the deficiencies in mothers's milk, for example: premature milk formula, alternating mother's milk with premature milk formula, additional additives to mother's milk and commercial fortifiers. Previous research of mother's milk fortifiers has shown that the biochemistry has positvely influenced their growth. Six patients were used in the experimental group and received 25% mother's milk and 75% fortifier. The control group consisted of eight babies who only received mother's milk. All the babies met the criteria and reached the 1600 gram weight by the time the study was completed. The Mann Whitney U test was used to calculate the results. No significant statistical growth was seen in any of the areas tested. It was concluded that mother's milk should be fortified, despite the results of the study, as mother's milk is definitely deficient in certain nutrients. It is possible to use mother's milk fortifiers in a stronger consentration.

Rapid and important cerebral developmental changes occur between the third trimester of gestation and the first postnatal months (Sidman and Rakic, 1982). Assessment of these changes in term and preterm infants is of great interest, as it provides insights into early brain development but also how early birth may affect normal brain development (Mewes et al. 2006).<p>Conventional brain magnetic resonance imaging (MRI) is a useful technique to provide structural information on brain development, and several studies have correlated brain structure modifications with specific learning or behavioral problems (Peterson et al. 2003, Woodward et al. 2005, Kapellou et al. 2006, Woodward et al. 2006). Nevertheless, this technique is not sensitive enough to evidence subtle microstructural changes. <p><p>Diffusion tensor imaging (DTI), which assesses and quantifies water diffusion in biological tissues at a microstructural level, may provide unique clues to the structure and geometric organization of the cerebral tissues (Le Bihan et al. 2001). DTI takes advantage of the fact that, in the brain, water molecules diffuse more easily in the direction of the fibers than orthogonally to study cortex and white matter (WM). DTI indices like fractional anisotropy (FA), which expresses the fraction of the magnitude of the diffusion tensor attributable to anisotropic diffusion, mean diffusivity (MD), which corresponds to the directionally averaged magnitude of water diffusion, and longitudinal and transverse diffusivity (λ// and λ⊥), which express respectively the parallel and perpendicular diffusion of water molecules, are used to indirectly quantify brain microstructure and evaluate brain damage (Hüppi et al. 1998, Miller et al. 2002, Ment et al. 2009, Liu et al. 2012). <p><p>Most previously published studies in neonates limited their analysis to particular zones of the WM, using regions of interest (ROI) to select regions where DTI values are expected to change. Approaches on the basis of ROIs have well-known limitations because strong a priori hypotheses about localization and extent of the effects of interest have to be made (Giuliani et al. 2005). Voxel-based methods of neuroimaging data analysis, such as statistical parametric mapping (SPM), do not have such limitations and have been successfully applied to study age-related DTI changes in adults, DTI differences between preterm and infants at term equivalent age, and brain structural asymmetries in infants (Ashtari et al. 2007, Snook et al. 2007, Gimenez et al. 2008, Dubois et al. 2010).<p>Studies correlating DTI indices at term equivalent age with later neurodevelopment are scarce and their analysis is limited to the WM, without exploring the cortex (Arzoumanian et al. 2003). Moreover, they use neuropsychological testing where language evaluation is combined with cognitive and motor scales to give an overall cognitive score (Krishnan et al. 2007, Rose et al. 2007, Rose et al. 2009).<p>The aims of this work were, using a voxel-based analysis of DTI sequences, 1) to evidence new brain regions that experience microstructural modifications along post-menstrual age (PMA) during early development of the human brain, and 2) to correlate regional brain microstructure at term equivalent age with subsequent cognitive, motor and language development at two years corrected age in a population of preterm infants.<p>We first investigated DTI changes in a population of 22 healthy preterm and 6 term infants covering the life period between 34 and 41 weeks PMA, and found that, besides the already-evidenced FA increase in the corticospinal tract (CST) and callosal radiations, the thalami and the thalamic radiations experienced linear microstructural changes. These changes were interpreted as a marker of regression of cytoplasmic arborization and proliferation of immature oligodendrocytes that wrapped around the axons well before the appearance of myelin (Aeby et al. 2009). Then we looked for nonlinear DTI changes, considering that many of biological processes that occur during development follow a nonlinear course. This yielded negative results, probably due to the small sample size. Therefore, in a second study, we searched for regional linear and nonlinear microstructural changes with PMA throughout the brain in a larger population (65 patients) composed exclusively of preterm neonates scanned between 35 and 43 weeks PMA. This study confirmed the linear FA changes with age previously described and, more importantly, evidenced nonlinear changes in brain structures around the right posterior superior temporal sulcus (STS) and in the right lateral occipitotemporal gyrus (LOTG), with FA decrease between 34 and 39 weeks followed by FA increase from 40 weeks to 43 weeks. The right STS belongs to the speech-processing network and is implicated in prosody but also in inter-individual communicative behavior and face processings in close association with the right LOTG. We suggest that the microstructural modifications in brain structures around the right STS and in the LOTG observed between 35 and 43 weeks of gestation in preterm infants could contribute to the functional maturation of these brain regions with increasing age, in a period of life where voices, prosody and faces represent extremely salient stimuli (Aeby et al. 2012).<p>In the second part of the thesis, we tested the hypothesis that abnormal local brain microstructure of preterm infants at term equivalent age would affect neurodevelopmental abilities at age 2 years. Therefore, we searched throughout the whole brain to correlate changes of the Bayley-III scores (cognitive, motor and language composite scores) with the regional distribution of MD, FA, λ// and λ⊥. We found that language abilities are negatively correlated to MD, λ// and λ⊥ in the left superior temporal gyrus (STG) in preterm infants. These findings suggest that higher MD, λ// and λ⊥ values at term- equivalent age in the left STG are associated with poorer language scores in later childhood. Consequently, this highlights the key role of the left STG for the development of language abilities in children and suggests that brain DTI might be an interesting tool to assess on an individual basis the development of language in the preterm.<p><p>To sum up, in this thesis, we showed that, besides the already-evidenced FA increase in the CST and corpus callosum, the thalami and the thalamic radiations experience linear microstructural changes in the early development of the human brain. We further showed that FA changes nonlinearly with age in brain structures around the right STS and in the right LOTG, which are key regions in verbal and non-verbal communicative behavior. We also showed that voxel-based DTI analysis is able to evidence microstructural changes in the lSTG that are negatively correlated with language development at two years in the preterm at the group level. These results highlight the key role of the lSTG in the development of language in the preterm and suggest that brain DTI might be an interesting tool to predict the development of language on an individual basis.<p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished