Changes in cranial base and craniocervical junction during growth in healthy individuals and in patients with Osteogenesis imperfecta
Year: 2012
Type: dissertation
Study design: Observational Study
Abstract: Cranial base and craniocervical junction anatomy can be evaluated from CT and MR scans, and lateral skull radiographs. Cranial base anatomy changes during growth, as the form of the anatomic structures and their relative positions alter. In disorders of compromised bone quality, abnormal changes in the craniocervical junction can lead to pathological conditions with possibly life-threatening neurological complications. In this investigation these issues have first been addressed by making skull base measurements of healthy growing individuals to determine the age-specific normative values used to evaluate cranial base structures. These normative values were then employed in the following analysis of growing patients suffering from osteogenesis imperfecta (OI), a disorder of bone fragility due to abnormal collagen composition. In healthy individuals cranial base measurements, young children demonstrated significantly different results from those of older growing individuals and adults. Thus studies on patients younger than 9 years should include age-appropriate controls. Significant individual variation in skull base measurements during growth may appear, as revealed by longitudinal observation. The observed wide ranges, and the fact that the position of the odontoid process in relation to skull base structures may individually display alternating up- and downward movements, are important to consider when conducting follow-up examinations. Nevertheless, a notable deviation from the documented normal values is suggestive of pathological development in the craniocervical junction. When comparing the age-specific normal values, skull base abnormalities were found to be present in approximately one fifth of OI patients; platybasia was the most frequent finding. Patients with haploinsufficiency mutations (which lead to a relatively mild phenotype) were less likely to have skull base abnormalities than patients with helical glycine substitutions. However, the strongest predictor of skull base abnormality was not the type of collagen mutation underlying OI but the clinical severity of the disorder, as expressed by the height Z-score. No evidence was found for a protective effect of bisphosphonate treatment, nor for the progression of craniocervical junction pathology with age. Based on this normative data and the observations made in patients with OI, age-appropriate screening limits for skull base pathology are proposed here, in addition to a recommendation for timing of radiological screening in patients with OI.
Source: Työväentutkimus Vuosikirja
Author: Arponen, Heidi
Language: English
Subfield: Genetics
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W2283554387