A morphometric analysis of the infant calvarium and dura

Abstract

Literature addressing the anatomic development of the dura and calvarium during childhood is limited. Nevertheless, histological features of a subdural neomembrane (NM), including its thickness and vascularity, developing in response to an acute subdural hematoma (SDH) have been compared to the dura of adults to estimate when an injury occurred. Therefore, we measured the morphometric growth of the calvarium and dura and the vascular density within the dura during infancy. The mean thicknesses of the calvarium and dura as a function of occipitofrontal circumference (OFC), as well as the mean number of vessels per 25 × field, were determined from the right parasagittal midparietal bone lateral to the sagittal suture of 128 infants without a history of head trauma. Our results showed that as OFC increased, the mean thicknesses of the calvarium and dura increased while the vascular density within the dura decreased. Our morphometric data may assist in the interpretation of subdural NM occurring during infancy. We recommend future investigations to confirm and extend our present data, especially by evaluating cases during later infancy and beyond as well as by sampling other anatomic sites from the calvarium. We also recommend morphometric evaluation of subdural NM associated with SDH in infancy and childhood.

Fig. 1

The thickness of the calvarium increases with increasing OFC. Pearson correlation coefficient = .569, r ² = .324, P < 0.01. (n = 128)

Fig. 2

The dura increases in thickness with increasing OFC in infancy. Pearson correlation coefficient = .370, r ² = .137, P < 0.01. (n = 128)

Fig. 3

The density of vessels in the dura gradually decreases with increasing OFC during infancy. Pearson correlation coefficient is −.218, r ² = .0474, P < 0.05. (n = 117)

Fig. 4

a The calvarium surfaces the dura of an infant with an OFC of 26 cm. The vertical bars indicate dimensions selected for measuring the thickness of the calvarium and dura. The horizontal marker equals 100 μm. Hematoxylin and eosin, 40×. b The calvarium surfaces the dura of an infant with an OFC of 33 cm. The vertical bars indicate dimensions selected for measuring the thickness of the calvarium and dura. The horizontal marker equals 100 μm. Hematoxylin and eosin, 40×. c The calvarium surfaces the dura of an infant with an OFC of 40 cm. The vertical bars indicate dimensions selected for measuring the thickness of the calvarium and dura. The horizontal marker equals 100 μm. Hematoxylin and eosin, 40×