Kim Annink

34 Chapter 2 models, it has been shown that PCs in lobules IX and X were less vulnerable for hypoxic-ischemia (26). Additionally, the lobes of the adult human cerebellum have a functional topographic organization, so the pattern of PC injury might be relevant for functional outcome (25,26). Literature about the topographic organization of the vermis in neonates with HIE is scarce as well as literature about differences in vulnerability of the vermis to hypoxia. Therefore, the aim of this study was to determine the distribution of PC injury in the vermis of term born neonates with HIE. METHODS Patient population In this retrospective cohort study, (near)-term neonates (36 until 42 weeks of gestational age) with HIE were included, who were treated with therapeutic hypothermia (born between 2008 and 2015) or would have qualified for therapeutic hypothermia according to the criteria of Azzopardi et al. (born between 2000 and 2008) and who underwent autopsy after neonatal death with hematoxylin and eosin (H&E) staining of the vermis (3). Exclusion criteria were perinatal asphyxia based on major congenital abnormalities, metabolic disorders, chromosomal abnormalities or poor quality of the sections of the vermis. No normotypic age-matched controls were available in this study. Parental consent was obtained for postmortem histopathological examination. The Medical Ethical Committee (MEC) of the UMC Utrecht confirmed that the ‘Medical Research Involving Human Subjects Act’ did not apply to this study and therefore an official approval of the MEC was not required (MEC # 18-167). The UMC Utrecht biobank approved the use of the rest tissue (biobank # 18-284). Histopathological examination Brains were removed during autopsy and before the slices could be cut they were dehydrated with ethanol 70%. Afterwards they were fixed in a 4% buffered formalin solution for four to six weeks (18). The vermis was cut midsagittally in 5-6 µm thick sections, mounted on coated slides and stained for H&E. From each patient one section was implemented. The H&E stained sections were used to examine the presence and the morphology of PCs using the light microscope Zeiss AXIO lab A1 and ZEN 1.2 lite software (Zeiss, CA, U.S.A). First, the sections of the vermis were photographed at various locations with