CEREBRAL AUTOREG & PERIVENTRICULAR LEUKOMALACIA IN PREMIES

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This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The primary analysis will examine the relationship between the diagnosis of PVL in the newborn period (by Cranial US, Preterm MR and Term MR) and the structual (One-Year MR) and functional (one-year neurodevelopmental) outcomes. Independent variables will be: binary (PVL/no PVL) and categorical (no PVL, focal PVL, diffuse PVL, focal and diffuse PVL). Dependent structural variables will be volume of myelinated WM and RA in WM. Dependent functional variables will be: neurologic outcome categorical, i.e. normal, abnormal without disability, abnormal with disability; development outcome continuous, i.e., global Bayley Scale score. The secondary analyses will explore clinical-anatomic correlations by examining the relationship between structural (One-Year MR) and functional (neurologic/cognitive) outcomes. Independent variables will be (1) volumes of WM (unmyelinated and total), cortical gray matter, subcortical gray matter, total brain; (2) RA levels in the standard WM locations; and (3) the concentration of NAA in the WM by 1H-MRS. The dependent variables will be (1) motor outcome (normal, diplegia, hemiplegia, quadriplegia), and (2) the individual Bayley Scale sub-scores, i.e. Mental Developmental Index (MDI) and the Psychomotor Developmental Index (PDI). Since the vast majority of myelin is formed after term, the Term MR studies are likely to demand a larger sample size to demonstrate statistically significant structural differences than the One-Year MR studies. To determine the required sample size we used the WM volume on the Term MR studies as the outcome of interest. We used our preliminary data and assumed that infants with WM injury in the newborn period are pressure passive while infants without WM injury are autoregulating. Based on these data and assuming a two-sample test at 0.05 level with a ratio of 3:1 between autoregulation vs pressure passive, we will require approximately 20 infants total to demonstrate a significant difference in volume o