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Development of striatum begins around 7th PCW when first cells originating in ganglionic eminence migrate and form striatal anlage. First inhomogeneities in internal organization are visible between 10th and 14th PCW. Development of internal organization has its peak between 20th and 24th PCW. After this period striatum undergoes perinatal and postnatal reorganization. The exact time of adult type of organization is not precisely determined in literature. The purpose of this study was to determine growth curve of striatum in order to correlate it with changes in intrinsic organization which underway in our laboratory. In addition, we correlate changes in volume with growth of hemispheric volume during fetal and early postnatal period, based on well- known corticostriatal relationship. Study involved 5 “normal” term infants, 15 normotypic developing premature infants with normal MRI and clinical parameters, 15 postmortem fetal brains from 13 till 40 PCW (Zagreb Neuroembryological Collection) and 5 normal infants age 1 month till 1 year. All groups were scanned by MRI device, control group at term, normotypic at the corrected term age and fetal brains after insertion in formalin. All volumes were measured on 3T MR images utilizing semi-automated and manual segmentation methods (MNI toolbox, available on the Internet). All data were analyzed using MathCalc statistical software (v 4.1, USA). Linear growth was observed in all measured data. Linear growth of striatum components, both caudate and putamen, left or right, follows increased volume of hemispheres and total brain volume from 13 PCW till age of one year postnatal. Peak of volume is around 24th PCW with the fastest growth between 20 and 28 PCW. Our study showed linear growth of observed structures (volume of nucleus caudatus, putamen and hemisphere) in fetal, neonatal and postnatal period with the peak of volume around 24th PCW. Showed results with peak around 24th PCW and the fastest growth between 20th and 28th PCW respond to transition according to structure of adult brain with modular organization which rearranges until the end of postnatal period (1st year of life). It is interesting that peak of the volume is achieved during maximum expression of modular. organization which also reflex intensive ingrowth of corticostriatal projections. The normative data we presented in this study will be used for correlation with development of modular organization and analysis of brains after hypoxic lesions. |
