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Surgical Neurology International 2023Osseous hyperpigmentation of the calvarium is an extremely rare finding with only few reported cases in literature.
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 -
Journal of Anatomy Feb 2022In 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...
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 -
Current Biology : CB Jul 2017The 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...
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 -
Cancers Feb 2022Meningiomas are the most common tumor of the central nervous system and can result in skeletal manifestations, including hyperostosis of the adjacent cranial bone,... (Review)
Review
Meningiomas are the most common tumor of the central nervous system and can result in skeletal manifestations, including hyperostosis of the adjacent cranial bone, enostoses, depressions, and enhanced vascular impressions. However, their identification in the paleopathological literature has been rare and few cases have received broad acceptance of the diagnosis. A review of the literature identified some 43 cases in which individuals were argued to have suffered from meningiomas. Most were seen in older individuals but were more likely to affect males. Eleven individuals exhibited hyperostosis, the most easily recognized indicator, usually located on the parietal bone; the hyperostotic region averaged 8 cm in diameter and 3.0 cm in height. Seven displayed lytic lesions with areas much smaller in size than the hyperostosis, and many had vascular changes. The other cases had indicators that varied greatly in terms of location and expression and included both sclerotic lesions and hollow areas. Several authors also suggested other possible causes of the lesions. The findings reflect the non-pathognomonic nature of the effects of meningiomas. However, given their likely frequency and potentially severe effects in ancient people, it is argued that they should be taken into consideration more frequently when performing differential diagnoses.
PubMed: 35205806
DOI: 10.3390/cancers14041058 -
Mechanical and morphological properties of parietal bone in patients with sagittal craniosynostosis.Journal of the Mechanical Behavior of... Jan 2022Limited information is available on the effect of sagittal craniosynostosis (CS) on morphological and material properties of the parietal bone. Understanding these...
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 -
Folia Morphologica 2021The 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...
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 -
International Journal of Surgery Case... Jul 2022The rare form and mildest variant of Langerhans cell histiocytosis is eosinophilic granuloma (EG). In the clinical presentation, EG can be monostotic, polyostotic, or...
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 -
Calcified Tissue International Nov 2019Increasing evidence has demonstrated the important role of autophagy in skeletal homeostasis; however, the role of autophagy in craniofacial bone development and...
Increasing evidence has demonstrated the important role of autophagy in skeletal homeostasis; however, the role of autophagy in craniofacial bone development and acquisition is largely unknown. In this study, we investigated the effect of autophagy suppression on craniofacial bone acquisition by deleting Fip200 or Atg5, two essential autophagy genes, using Osterix-Cre (Osx-Cre). We found that the Osx-Cre transgene mildly decreased the bone mass of parietal bone but not frontal bone, and did not affect cranial base bone mass in adult mice. In the cranial vault, Fip200 or Atg5 deletion similarly decreased 50% bone mass of neural crest-derived frontal bone; Atg5 deletion decreased 50% and Fip200 deletion decreased 30% bone mass of mesoderm-derived parietal bone. In the cranial base, Fip200 or Atg5 deletion similarly decreased 30% bone mass of neural crest-derived presphenoid bone; Atg5 deletion decreased 30% and Fip200 deletion decreased 16% bone mass of mesoderm-derive basioccipital bone. Lastly, we used doxycycline treatment to inhibit the Osx-Cre expression until 2 months of age and showed that postnatal Fip200 deletion led to cranial vault bone mass decrease in association with a small increase in both bone volume/tissue volume and tissue mineral density. Altogether, this study demonstrated the important role of autophagy in craniofacial bone acquisition during development and postnatal growth.
Topics: Animals; Autophagy; Bone Development; Facial Bones; Mice; Mice, Transgenic; Skull
PubMed: 31372669
DOI: 10.1007/s00223-019-00593-2 -
The International Journal of... 2017The mammalian skull vault is a highly regulated structure that evolutionally protects brain growth during vertebrate development. It consists of several membrane bones... (Review)
Review
The mammalian skull vault is a highly regulated structure that evolutionally protects brain growth during vertebrate development. It consists of several membrane bones with different tissue origins (e.g. neural crest-derived frontal bone and mesoderm-derived parietal bone). Although membrane bones are formed through intramembranous ossification, the neural crest-derived frontal bone has superior capabilities for osteoblast activities and bone regeneration via TGF, BMP, Wnt, and FGF signaling pathways. Neural crest (NC) cells are multipotent, and once induced, will follow specific paths to migrate to different locations of the body where they give rise to a diverse array of cell types and tissues. Recent studies using genetic mouse models have greatly advanced our knowledge of NC cell induction, proliferation, migration and differentiation. Perturbations or disruptions of neural crest patterning lead to severe developmental defects or diseases. This review summarizes recent discoveries including novel functions of genes or signaling molecules that are capable of governing developmental processes of neural crest patterning, which may function as a gene regulatory network in controlling skull development. The proposed regulatory network will be important to understand how the signaling pathways and genes converge to regulate osteoblast activities and bone formation, which will be beneficial for the potential identification of molecular targets to prevent or alleviate human diseases or disorders involving defective neural crest development.
Topics: Animals; Cranial Nerves; Gene Expression Regulation, Developmental; Mice; Neural Crest; Signal Transduction; Skull
PubMed: 29139535
DOI: 10.1387/ijdb.170051gc