Authors: Devon van Eck, Blessing Ndlovu, Mohammed Ouwais Abdul Sattar...

BACKGROUND

Osseous hyperpigmentation of the calvarium is an extremely rare finding with only few reported cases in literature.

CASE DESCRIPTION

The case is of a 59-year-old Caucasian male who presented with an acute history of generalized tonic clonic seizures and progressive weakness of the right upper limb. He had a background history of a malignant melanoma which had been resected from his left external acoustic meatus 4 weeks prior. Neuroimaging of the brain showed an intra-axial space-occupying lesion in his left parietal lobe with no associated osseous changes. A left mini parietal craniotomy was performed which revealed black discoloration of the parietal bone. The lesion was successfully resected and the bone flap was secured back in place. The patient was discharged on the 4 day postoperatively with no complications. The unusual finding of black discoloration of the calvarium was found to be secondary to adolescent tetracycline use.

CONCLUSION

Calvarial hyperpigmentation is a phenomenon encountered incidentally and will often come as surprise for surgeons. Once encountered, thorough history taking and examination should be done to investigate the cause.

PubMed: 37680939
DOI: 10.25259/SNI_493_2023

Authors: Ana Sofia Pereira-Pedro, Emiliano Bruner

In adult humans, the orbits vary mostly in their orientation in relation to the frontal bone profile, while the orientation of the cranial base and face are associated with the anteroposterior dimensions of the parietal bone. Here we investigate the effect of parietal bone length on the orientation of the orbits, addressing craniofacial integration and head orientation. We applied shape analysis to a sample of computed tomography scans from 30 adult modern humans, capturing the outlines of the parietal and frontal bones, the orbits, and the lateral and midline cranial base, to investigate shape variation, covariation, and modularity. Results show that the orientation of the orbits varies in accordance with the anterior cranial base, and in association with changes in parietal bone longitudinal extension. Flatter, elongated parietal bones are associated with downwardly oriented orbits and cranial bases. Modularity analysis points to a significant integration among the orbits, anterior cranial base, and the frontal profile. While the orbits are morphologically integrated with the adjacent structures in terms of shape, the association with parietal bone size depends on the spatial relationship between the two blocks. Complementary changes in orbit and parietal bone might play a role in accommodating craniofacial variability and may contribute to maintain the functional axis of the head. To better understand how skull morphology and head posture relate, future studies should account for the spatial relationship between the head and the neck.

Topics: Adult; Face; Frontal Bone; Head; Humans; Parietal Bone; Skull; Skull Base

PubMed: 34498271
DOI: 10.1111/joa.13543

Authors: Sara Ajami, Naiara Rodriguez-Florez, Juling Ong...

Limited information is available on the effect of sagittal craniosynostosis (CS) on morphological and material properties of the parietal bone. Understanding these properties would not only provide an insight into bone response to surgical procedures but also improve the accuracy of computational models simulating these surgeries. The aim of the present study was to characterise the mechanical and microstructural properties of the cortical table and diploe in parietal bone of patients affected by sagittal CS. Twelve samples were collected from pediatric patients (11 males, and 1 female; age 5.2 ± 1.3 months) surgically treated for sagittal CS. Samples were imaged using micro-computed tomography (micro-CT); and mechanical properties were extracted by means of micro-CT based finite element modelling (micro-FE) of three-point bending test, calibrated using sample-specific experimental data. Reference point indentation (RPI) was used to validate the micro-FE output. Bone samples were classified based on their macrostructure as unilaminar or trilaminar (sandwich) structure. The elastic moduli obtained using RPI and micro-FE approaches for cortical tables (E 3973.33 ± 268.45 MPa and E 3438.11 ± 387.38 MPa) in the sandwich structure and diploe (E1958.17 ± 563.79 MPa and E 1960.66 ± 492.44 MPa) in unilaminar samples were in strong agreement (r = 0.86, p < .01). We found that the elastic modulus of cortical tables and diploe were correlated with bone mineral density. Changes in the microstructure and mechanical properties of bone specimens were found to be irrespective of patients' age. Although younger patients are reported to benefit more from surgical intervention as skull is more malleable, understanding the material properties is critical to better predict the surgical outcome in patients <1 year old since age-related changes were minimal.

Topics: Child; Craniosynostoses; Female; Humans; Infant; Parietal Bone; X-Ray Microtomography

PubMed: 34773914
DOI: 10.1016/j.jmbbm.2021.104929

Authors: Jonathan R Whitlock

The posterior parietal cortex, along with temporal and prefrontal cortices, is one of the three major associative regions in the cortex of the mammalian brain. It is situated between the visual cortex at the caudal pole of the brain and the somatosensory cortex just behind the central sulcus. Technically, any cortex covered by the parietal bone is referred to as 'parietal cortex', but the posterior sector, formally referred to as posterior parietal cortex, is indeed its own functional section of cortex, consisting of Brodmann's areas 5, 7, 39, and 40 in humans, areas 5 and 7 in macaques, and area 7 in rodents (Figure 1). Whereas the anterior parietal cortex in humans comprises primary somatosensory areas, the posterior parietal cortex has several higher-order functions. It is referred to as an 'associative' cortical region because it is neither strictly sensory nor motor, but combines inputs from a number of brain areas including somatosensory, auditory, visual, motor, cingulate and prefrontal cortices, and it integrates proprioceptive and vestibular signals from subcortical areas.

Topics: Animals; Humans; Mammals; Parietal Lobe

PubMed: 28743011
DOI: 10.1016/j.cub.2017.06.007

Authors: Osama N Dukmak, Sulaiman M S Abualia, Yara J I Meqbil...

BACKGROUND

The rare form and mildest variant of Langerhans cell histiocytosis is eosinophilic granuloma (EG). In the clinical presentation, EG can be monostotic, polyostotic, or can encompass many organs. The parietal bone is the most common location of the skull bones that are affected by EG. So far, there have been no reported cases of EG with skull odor as an unexplained presentation.

CASE PRESENTATION

An 8-year-old girl presented with a 4 months history of a right parietal bone swelling of the skull with an offensive odor. There was no discharge and no history of vomiting or trauma. An MRI scan of the brain showed swelling with a bone lesion of the right parietal bone. Infection was the source of the swelling and the bad odor. Treatment was done by surgical excision of the lesion.

CONCLUSION

EG has a variety of presentations and should be suspected when tenderness and local swelling are present. Radiography was found to be helpful in the diagnosis and surgical treatment was done to manage the case.

PubMed: 35780646
DOI: 10.1016/j.ijscr.2022.107371

Authors: Stanislava Eisová, Gizéh Rangel de Lázaro, Hana Píšová...

Cranial bone thickness varies among modern humans, and many factors influencing this variability remain unclear. Growth hormones and physical activity are thought to influence the vault thickness. Considering that both systemic factors and energy supply influence the vascular system, and taking into account the structural and biomechanical interaction between endocranial vessels and vault bones, in this study we evaluate the correlation between vascular and bone diameters. In particular, we tested the relationship between the thickness of the parietal bone (which is characterized, in modern humans, by a complex vascular network) and the lumen size of the middle meningeal and diploic vessels, in adult modern humans. Our results show no patent correlation between the thickness of parietal bone and the size of the main vascular channels. Values and distributions of the branching patterns, as well as anatomical relationships between vessels and bones, are also described in order to provide information concerning the arrangement of the endocranial vascular morphology. This information is relevant in both evolutionary and medical contexts. Anat Rec, 299:888-896, 2016. © 2016 Wiley Periodicals, Inc.

Topics: Adult; Biological Evolution; Cerebral Arteries; Female; Fossils; Humans; Male; Parietal Bone; Skull

PubMed: 27072555
DOI: 10.1002/ar.23348

Authors: Cagla Cicek, Gaye Filinte, Tufan Hicdonmez...

AIM

To understand the characterization of the ossification process both in the synostotic suture, and the adjacent parietal bone.

MATERIAL AND METHODS

The surgical procedure for the 28 patients diagnosed with sagittal synostosis consisted of removing the synostotic bone as a whole, if possible, "Barrel-Stave" relaxation osteotomies, and strip osteotomies to the parietal and temporal bones perpendicular to the synostotic suture. The synostotic (group I) and parietal (group II) bone segments are obtained during osteotomies. Atomic absorption spectrometry was used to determine the amount of calcium in both groups, which is an indicator of ossification. Scanning electron microscopy and immunohistochemistry were employed to assess trabecular bone formation, osteoblastic density, and osteopontin, which is one of the in vivo indicators of new bone formation.

RESULTS

Histopathologically, trabecular bone formation scores did not indicate any significant difference between the groups. However, the osteoblastic density and calcium accumulation in group I were higher than those in group II, and the difference was significant. Osteopontin staining scores in cells showing membranous and cytoplasmic staining with osteopontin antibodies significantly increased in group II.

CONCLUSION

In this study, we found reduced differentiation of osteoblasts despite their increase in number. Moreover, the osteoblastic maturation rate was low in synostotic sutures, bone resorption becomes slower than new bone formation, and the remodeling rate is low in sagittal synostosis.

Topics: Humans; Child; Infant; Osteopontin; Cranial Sutures; Parietal Bone; Calcium; Craniosynostoses; Sutures

PubMed: 36951024
DOI: 10.5137/1019-5149.JTN.41370-22.2

Authors: J Naidoo, J S Luckrajh, L Lazarus...

BACKGROUND

The parietal foramen (PF) is a small inconsistent aperture located at the border of the middle 1/3 and posterior 1/3 of the parietal bone near the sagittal suture and is considered an emissary foramen. Cranial emissary foramina are of utmost importance due to the structures that traverse the foramen. Variations in these foramina are common. Knowledge of the PF is important when performing neurosurgical procedures as the emissary vessels are at risk.

MATERIALS AND METHODS

The present study used 100 dry adult calvaria to determine the frequency of PF, the diameter of the PF, as well as topography of the PF (using the sagittal suture as an anatomical landmark).

RESULTS

A total of 32% of calvaria had PF present bilaterally; whilst 35% of calvaria had unilateral PF. The study also reports 5% calvaria in which PF were present on the sagittal suture. The mean diameter recorded was 1.55 mm (0.74-3.08 mm), and the mean distance between the lateral margin of the PF and the sagittal suture was 9.02 mm (4.44-18.20 mm).

CONCLUSIONS

Knowledge of the incidence and topography of the PF may aid neurosurgeons in creating and adjusting techniques and procedures in order to mitigate the risk of injury to emissary veins and other structures emerging from the PF.

Topics: Cranial Sutures; Incidence; Parietal Bone; Sphenoid Bone; Veins

PubMed: 33241848
DOI: 10.5603/FM.a2020.0140

Authors: Xiao Xiao, Qiang Li, Yan Ju...

BACKGROUND

Hemangiopericytoma (HPC) is a tumor originating from pericytes surrounding the capillary walls. Most HPCs grow slowly, but some display aggressive growth. Treatment for HPC is total resection or resection plus adjuvant radiation.

CASE PRESENTATION

A 14-year-old girl presented with a blood vessel-rich tumor with a smooth surface located on the left side of the parietal bone, attached to the inner surface of the skull. The dura was completely intact. The final diagnosis was HPC based on the histopathologic and immunohistochemical findings. The patient underwent total resection of the tumor and cranioplasty. The dura was not incised because of the lack of invasive growth. Within the 2-year follow-up, the patient showed an excellent prognosis without any local recurrence or positive radiologic features.

CONCLUSION

The patient presented with common intracranial hypertension symptoms. A blood vessel-rich tumor with a smooth surface was attached to the inner surface of the skull with the dura completely intact. Simple surgical resection without radiotherapy offered an excellent prognosis during 2 years of follow-up.

PubMed: 36915721
DOI: No ID Found