Intracranial volume, cranial thickness, and hyperostosis frontalis interna in the elderly

Morpho-radiological and brain endocast analysis in the study of Hyperostosis Frontalis Interna (HFI): A combined approach

The purpose of this study is to anatomically evaluate the impact on the patient intra vitam of an endocranial condition on a late 20th century skull housed in the Section of Legal Medicine of the University of Foggia (Foggia, Apulia, Italy). After performing a retrospective diagnosis, the condition is framed in the broader context of studies on this pathology. An anthropological and radiological analysis (X-ray and CT scan imaging) made it possible to confirm the preliminary information and to detail the osteological diagnosis of HFI. In order to assess the impact on the cerebral surface of the endocranial growth a 3D endocast was obtained using the Software OrtogOnBlender. The skull is demonstrated to have belonged to a female senile individual known, from limited documentary evidence, to have suffered from a psychiatric condition during her life. The final diagnosis is hyperostosis frontalis interna (HFI), Type D. Although a direct correlation between the demonstrated intracranial bony growth and the onset of the patient's psychiatric condition is difficult to retrospectively ascertain, the pressure exerted on this female individual's frontal lobe may have contributed to further degenerative behavioural changes in the last years of her life. This case adds to previous knowledge, especially from the palaeopathological literature, on this condition and, for the first time, presents a neuroanatomical approach to assess the global impact of the disease.

Schizophrenia and Hyperostosis Frontalis Interna with History of Head Injury

Hyperostosis frontalis interna is an irregular thickening of the frontal bone. Its etiology is unknown. It has been rarely linked with schizophrenia and head injury. Case Presentation. We describe an unusual case of a 44-year-old female with schizophrenia and hyperostosis frontalis interna having a history of head trauma. At the age of 3 years, she had a head injury that could be classified as mild traumatic brain injury. She presents a family history of schizophrenia. She was admitted for resistant schizophrenic disorder. The cranial computed tomography showed bilateral and asymmetrical hyperostosis of the frontal bone that was more pronounced on the right side. This corresponds to the impact of the trauma with frontal atrophy without any metabolic or endocrinal abnormalities. Conclusion. We surmise that the long-term pathological effects of traumatic brain injury, including hyperostosis frontalis interna, are likely to interact with genetic vulnerability and may lead to schizophrenic disorder.

The Comparison of Piriform Aperture, Paranasal Sinuses, and Cranial Dimensions

OBJECTIVE

Piriform aperture, paranasal sinuses, and the cranium dimensions were compared with each other and we investigated the alterations depending on the age and gender in these structures. Before the endoscopic sinus surgery, anatomic variations in sinusoidal region and the occurring differences should be considered. The detection of these variations plays important roles in the prevention of complications which may happen in surgery or in obtaining a successful surgical result.

MATERIALS AND METHODS

Piriform aperture maximum width, frontal sinuses, sphenoidal sinuses, maxillary sinuses, and cranium widths and height length was measured from the regions that we were determined. Three hundred ninety three cases' computed tomography images were compared. The individuals without any head trauma, pathology, and surgical history in sinusoidal region were analyzed retrospectively. The detected measurements were studied among the paranasal sinuses, piriform aperture, and calvaria dimensions.

RESULTS

It was observed that the dimensions of paranasal sinuses were decreased and the dimension of piriform aperture was increased depending on age. In all individuals, a relationship in positive direction in a manner that piriform aperture width increases as the size of the cranium width increases. Morphologic alterations take place in the dimensions of paranasal sinuses as a result of bone deformations occurring in the bone structure depending age and gender in adult individuals.

Dysostosis in mucopolysaccharidosis type 2: A case of longitudinal follow up and literature review

Mucopolysaccharidosis type 2 is a congenital lysosomal disease characterized by iduronate-2-sulfatase deficiency, which leads to excessive accumulation of glycosaminoglycans in tissue. Dysostosis, which primarily involves decreased bone mineralization with morphological changes in the bone, is a major skeletal condition in mucopolysaccharidosis, but its pathophysiology is not well known. Here, we report a case of mucopolysaccharidosis type 2 diagnosed at the age of 2 years with longitudinal follow-up data for more than 15 years. Although the patient underwent bone marrow transplantation, the developmental quotient did not improve, and cranial hyperostosis progressed prominently with a faintly dilated perivascular space. Other dysostoses and contraction of the joints were observed but did not improve either.

Comparative Analysis of Femoral Macro- and Micromorphology in Males and Females With and Without Hyperostosis Frontalis Interna: A Cross-Sectional Cadaveric Study

We hypothesized that subjects with hyperostosis frontalis interna (HFI), which represents local, endocranial thickening of the frontal bone, would express extra-calvarial manifestations of this condition. Therefore, we compared femoral bone mineral density, geometry, and microarchitecture of males and females with HFI to those without this condition as well as between males and females with HFI. The sample was taken from human donor cadavers, 38 males (19 with and 19 without HFI) and 34 females (17 with and 17 without HFI) that were age-matched within the same sex. The specimens of femoral bones were scanned using microcomputed tomography and dual-energy X-ray absorptiometry (DXA). Parameters of hip structure analysis (HSA) were calculated from data derived from DXA scans. Females with HFI had increased cortical bone volume fraction and their cortical bone was less porous compared to females without HFI. Males with HFI showed microarchitectural differences only with the trabecular bone. They had increased bone volume fraction and decreased trabecular separation compared to males without HFI, although with borderline significance. These microarchitectural changes did not have significant impact on femoral geometry and bone mineral density. The same, still unknown etiological factor behind HFI might be inducing changes at the level of bone microarchitecture at a remote skeletal site (femoral bone), in both sexes. These alterations still do not have the magnitude to induce obvious, straightforward overall increase of bone mineral density measured by DXA. HFI could be a systemic phenomenon that affects both males and females in a similar manner.

Micro-computed Tomography Study of Frontal Bones in Males and Females with Hyperostosis Frontalis Interna

Hyperostosis frontalis interna (HFI) represents irregular thickening of the endocranial surface of the frontal bone, mostly seen in postmenopausal females. The microarchitecture of this condition is poorly studied. The aim of this cross-sectional autopsy study was to investigate and compare microarchitectural structure of the frontal bone affected with HFI in both sexes and to test whether HFI severity could be distinguished at the microarchitectural level. The sample was taken from human donor cadavers, 19 males (61 ± 15 years old) and 17 females (75 ± 15 years old). After classification of HFI severity (type A, B, C or D), samples of the frontal bone were taken and scanned using micro-computed tomography. Bone volume fraction was higher and total porosity lower only in the outer table of males with HFI, compared to females with HFI. Mean total sample thickness differed only between males with HFI type A and D. Bone microarchitecture between males and females with corresponding HFI types (e.g., male with type A versus female with type A) differed only in HFI type C regarding the fractal dimension of diploe. The degree of anisotropy differed between HFI subtypes in males, but the post hoc analysis revealed no significant differences between individual groups. Other microarchitectural parameters did not differ among males with different HFI subtypes, as well in females, in any part of the frontal bone. There is no difference in microarchitectural structure of the frontal bone between males and females with HFI, in general aspect and within corresponding HFI subtypes. HFI severity could not be distinguished at the microarchitectural level, neither in males nor in females.

Changes in the intracranial volume from early adulthood to the sixth decade of life: A longitudinal study

Normal brain-aging occurs at all structural levels. Excessive pathophysiological changes in the brain, beyond the normal one, are implicated in the etiology of brain disorders such as severe forms of the schizophrenia spectrum and dementia. To account for brain-aging in health and disease, it is critical to study the age-dependent trajectories of brain biomarkers at various levels and among different age groups. The intracranial volume (ICV) is a key biological marker, and changes in the ICV during the lifespan can teach us about the biology of development, aging, and gene X environment interactions. However, whether ICV changes with age in adulthood is not resolved. Applying a semi-automatic in-house-built algorithm for ICV extraction on T1w MR brain scans in the Dutch longitudinal cohort (GROUP), we measured ICV changes. Individuals between the ages of 16 and 55 years were scanned up to three consecutive times with 3.32±0.32 years between consecutive scans (N = 482, 359, 302). Using the extracted ICVs, we calculated ICV longitudinal aging-trajectories based on three analysis methods; direct calculation of ICV differences between the first and the last scan, fitting all ICV measurements of individuals to a straight line, and applying a global linear mixed model fitting. We report statistically significant increase in the ICV in adulthood until the fourth decade of life (average change +0.03%/y, or about 0.5 ml/y, at age 20), and decrease in the ICV afterward (-0.09%/y, or about -1.2 ml/y, at age 55). To account for previous cross-sectional reports of ICV changes, we analyzed the same data using a cross-sectional approach. Our cross-sectional analysis detected ICV changes consistent with the previously reported cross-sectional effect. However, the reported amount of cross-sectional changes within this age range was significantly larger than the longitudinal changes. We attribute the cross-sectional results to a generational effect. In conclusion, the human intracranial volume does not stay constant during adulthood but instead shows a small increase during young adulthood and a decrease thereafter from the fourth decade of life. The age-related changes in the longitudinalmeasure are smaller than those reported using cross-sectional approaches and unlikely to affect structural brain imaging studies correcting for intracranial volume considerably. As to the possible mechanisms involved, this awaits further study, although thickening of the meninges and skull bones have been proposed, as well as a smaller amount of brain fluids addition above the overall loss of brain tissue.

Skull Abnormalities in Cadavers in the Gross Anatomy Lab

Background

The skull encompasses and houses one of the most important organs in the body—the brain—and like all tissues in the body, it is comprised of living cells that are constantly remodeling as this maintains the strength and homeostasis of the bone. In the present study, abnormal bone growth patterns were observed and the possible causes of said findings were investigated in multiple cadaver skulls dissected during head and neck anatomy courses at Detroit Mercy Dental over the past year. There are many factors, both intrinsic and extrinsic, with differences in stimulation to the skull resulting in skull abnormalities. Materials and Methods. For this study, skull abnormalities were examined from 65 formalin-embalmed cadaver heads, obtained from the Gross Anatomy Laboratory at the University of Detroit Mercy School of Dentistry between the years 2016 and 2019. We have recorded the age, sex, and previous chief medical issues of all lab specimens used in the study. Skulls were later evaluated for possible indications of bone disease such as hypertosis frontalis interna (HFI) or Paget's disease.

Results

Among the sixty-five specimens provided to the Detroit Mercy Dental cadaver lab, 19 specimens (29%) were found to present with irregular, undulating, thickening of the frontal bone internal surface. The findings located on the skulls closely resembled the gross anatomic appearance of HFI or Paget's disease; however, a conclusive diagnosis of these skull abnormalities cannot be made without a pathologist biopsy and radiological examination. Twelve of the nineteen specimens that displayed possible bone disease, approximating 63% prevalence, were females; their ages ranged from 68 to 95 years old. Thus, seven of the nineteen specimens exhibiting features of skull abnormalities, approximating 36% prevalence, were males with ages ranging from 70 to 103 years old. In addition, five of these nineteen specimens collected (26% prevalence) had been diagnosed with neurological disorders, including Alzheimer's, dementia, depression, and Parkinson's disease. In the current study, the proportion of specimens exhibiting skull abnormalities was higher compared to the overall prevalence observed in previous studies.

Conclusion

Possible causes of observed anatomical abnormalities in the skull of cadavers of a gross anatomy laboratory were investigated, and it was determined that hypertosis frontalis interna (HFI) may contribute to such abnormalities. This is a condition that affects bone growth in the frontal skull. Our numbers of skull abnormalities were higher than previous studies and might be due to the fact that HFI was predominately present as an incidental finding during imaging of postmenopausal females or observed postmortem in cadavers. In addition, Paget's disease or hormonal imbalances could also result in similar features, and thus cannot be ruled out as a plausible cause. Paget's disease causes the bone to deposit at a faster rate than normal, which will result in thick and brittle bone. Studies that will involve further examination of new cadavers for the presence of HFI is needed, either using biopsy specimens and/or radiological examination to explore possible causes for the abnormal bone growth in the frontal bone.

A microscopic evaluation of Paget's disease of bone from a Byzantine monastic crypt in Jordan

Paget's disease of bone (PDB) is a metabolic bone disease that has been present in human populations for over 2000 years, with the earliest cases reported in Western Europe. Now present globally, PDB is one of the most common metabolic bone diseases in modern populations. This study details possible PDB of an adult male (MNR-EN Skull 3) with abnormally thickened cranial bones (17 mm). The skull was recovered from commingled skeletal remains excavated from the Robebus crypt at the Byzantine monastery of Mount Nebo, Jordan (c. late 4-7^th C). Micro-CT imaging and histological sections of the bone samples revealed an abnormal pattern of bone remodeling, with atypical osteon formation, convoluted and enlarged trabeculae, and an overall pattern of highly vascularized bone. Polarized microscopy produced a mix of woven bone and lamellar bone, the mosaic pattern of atypical bone remodeling indicative of PDB. Coupled with the dense, thickened nature of the vault bones, these data suggest that the individual had PDB. To our knowledge, this represents the earliest evidence of PDB in the Middle East supported by micro-analysis, and adds to the emerging paleopathological literature involving commingled skeletal remains and the potential for identifying unique disease processes.

Hyperostosis frontalis interna as an age-related phenomenon - Differences between males and females and possible use in identification

Hyperostosis frontalis interna (HFI) is a condition manifested by thickening of the inner surface of the frontal bone and it could be useful when dealing with the identification of human remains in various anthropological and forensic investigations. We compared the macroscopic appearance and morphologic (metric) features of the skulls in cases with and without HFI, in both sexes, and wanted to establish whether age determined occurrence of HFI. To achieve this aim, we performed prospective autopsy study, covering ten-year period (2007-2016). Study group consisted of southeast Europe Caucasian subjects, with determined age and sex. The severity of HFI was classified by two forensic pathologists independently, according to the four types (A-D) proposed by Hershkovitz et al. Thicknesses of the frontal and temporal bones, as well as the longitudinal and frontal diameters of the skulls were measured. The sample consisted of 35 males and 112 females with HFI, and 55 males and 202 females without HFI (404 individuals in total). Type B was the most common type of HFI among males (45%) and type C among females (41%). HFI type D was almost four times more common in females than in males (OR = 3.73). Frontal and temporal bones were thicker in all subjects who have HFI. Thickness of the skull was not age-dependent, in the entire sample, or in subjects with HFI, or in the control group (in all the cases Spearman's Rho was <0.3). Age seemed to be a predicting factor for HFI occurrence only in females. Females younger than 55 years have similar risk for HFI occurrence as males. An unidentified skull with the general markers of old age and severe form HFI is most probably from a female decedent.

Frontal Bone Fracture Patterns Suggesting Involvement of Optic Canal Damage

PURPOSE

Fracture of the frontal bone can be accompanied by damage to the optic canal. The present study uses finite element analysis to identify fracture patterns, suggesting the involvement of the optic canal.

METHODS

Ten finite-element skull models were generated from computer tomography data of 10 persons. Then, dynamic analyses simulating collision of a 2-cm-radius brass ball to 6 regions on the frontal bone in the 10 models were performed. Fracture patterns presented by the frontal bone in the 60 experiments were observed, and all those involving the optic canal were selected. Commonalities of the selected fracture patterns were identified.

RESULTS

Fracture of the optic canal was observed in 9 of the 60 patients. In all 9 patients, fracture existed on the anterior and posterior walls of the frontal sinus and on the superior orbital wall.

CONCLUSION

When the anterior and posterior walls of the frontal sinus and the superior orbital wall are all broken, the optic canal is highly likely to be involved in the damage. When this pattern is observed in emergency examination, preventive decompression of the optic nerve should be considered to avoid potential occurrence of blindness.

Sex determination of a Tunisian population by CT scan analysis of the skull

It is widely accepted that the estimation of biological attributes in the human skeleton is more accurate when population-specific standards are applied. With the shortage of such data for contemporary North African populations, it is duly required to establish population-specific standards. We present here the first craniometric standards for sex determination of a contemporary Tunisian population. The aim of this study was to analyze the correlation between sex and metric parameters of the skull in this population using CT scan analysis and to generate proper reliable standards for sex determination of a complete or fragmented skull. The study sample comprised cranial multislice computed tomography scans of 510 individuals equally distributed by sex. ASIR^TM software in a General Electric^TM workstation was used to position 37 landmarks along the volume-rendered images and the multiplanar slices, defining 27 inter-landmark distances. Frontal and parietal bone thickness was also measured for each case. The data were analyzed using basic descriptive statistics and logistic regression with cross-validation of classification results. All of the measurements were sexually dimorphic with male values being higher than female values. A nine-variable model achieved the maximum classification accuracy of 90% with -2.9% sex bias and a six-variable model yielded 85.9% sexing accuracy with -0.97% sex bias. We conclude that the skull is highly dimorphic and represents a reliable bone for sex determination in contemporary Tunisian individuals.

Hyperostosis frontalis interna in female historic skeletal populations: Age, sex hormones and the impact of industrialization

OBJECTIVES

This analysis aims to investigate the impact of industrialization on the prevalence of Hyperostosis Frontalis Interna (HFI), focusing on the roles of age and parity to examine the claim that longevity and changing reproductive patterns have led to increased rates in modern populations.

MATERIALS AND METHODS

A total of 138 individuals from two documented London skeletal assemblages of the Industrial period were analyzed employing macroscopic observation, digital radiography and MicroCT scanning to establish the prevalence rates of HFI according to modern clinical standards. Statistical analysis was also undertaken on a sub-sample of 51 females of post-menopausal age to identify any relationship between parity and HFI.

RESULTS

The majority of cases of HFI were found in older females, reflecting clinical observations. The prevalence rates of HFI corresponded well to those predicted from the proportion of old age females present within populations. Age was therefore shown to be a predominant factor in HFI presence. A plateau in HFI prevalence was noted from the age of 50-59 years onwards. No statistically significant relationship was found between parity and HFI.

DISCUSSION

When recorded consistently, HFI was positively correlated with age and longevity but had also increased among old age females over time. Our results suggest that nulliparity co-occurs with HFI but is not a primary factor in its pathogenesis. Key factors in HFI presence in females are likely to be increased androgens and the dysregulation of insulin and insulin-like growth factor-1.

3D-Microarchitectural patterns of Hyperostosis frontalis interna: a micro-computed tomography study in aged women

Although seen frequently during dissections and autopsies, Hyperostosis frontalis interna (HFI) - a morphological pattern of the frontal bone thickening - is often ignored and its nature and development are not yet understood sufficiently. Current macroscopic classification defines four grades/stages of HFI based on the morphological appearance and size of the affected area; however, it is unclear if these stages also depict the successive phases in the HFI development. Here we assessed 3D-microarchitecture of the frontal bone in women with various degrees of HFI expression and in an age- and sex-matched control group, hypothesizing that the bone microarchitecture bears imprints of the pathogenesis of HFI and may clarify the phases of its development. Frontal bone samples were collected during routine autopsies from 20 women with HFI (age: 69.9 ± 11.1 years) and 14 women without HFI (age: 74.1 ± 9.7 years). We classified the HFI samples into four groups, each group demonstrating different macroscopic type or stage of HFI. All samples were scanned by micro-computed tomography to evaluate 3D bone microarchitecture in the following regions of interest: total sample, outer table, diploe and inner table. Our results revealed that, compared to the control group, the women with HFI showed a significantly increased bone volume fraction in the region of diploe, along with significantly thicker and more plate-like shaped trabeculae and reduced trabecular separation and connectivity density. Moreover, the inner table of the frontal bone in women with HFI displayed significantly increased total porosity and mean pore diameter compared to controls. Microstructural reorganization of the frontal bone in women with HFI was also reflected in significantly higher porosity and lower bone volume fraction in the inner vs. outer table due to an increased number of pores larger than 100 μm. The individual comparisons between the control group and different macroscopic stages of HFI revealed significant differences only between the control group and the morphologically most pronounced type of HFI. Our microarchitectural findings demonstrated clear differences between the HFI and the control group in the region of diploe and the inner table. Macroscopic grades of HFI could not be distinguished at the level of bone microarchitecture and their consecutive nature cannot be supported. Rather, our study suggests that only two different types of HFI (moderate and severe HFI) have microstructural justification and should be considered further. It is essential to record HFI systematically in human postmortem subjects to provide more data on the mechanisms of its development.

Evaluation of morphological changes in the adult skull with age and sex

The morphology of the brain and skull are important in the evaluation of the aging human; however, little is known about how the skull may change with age. The objective of this study was to evaluate the morphological changes of the adult skull using three-dimensional geometric morphometric analysis of thousands of landmarks with the focus on anatomic regions that may be correlated with brain atrophy and head injury. Computed tomography data were collected between ages 20 and 100. Each scan was segmented using thresholding techniques. An atlas image of a 50th percentile skull was registered to each subject scan by computing a series of rigid, affine, and non-linear transformations between atlas space and subject space. Landmarks on the atlas skull were transformed to each subject and partitioned into the inner and outer cranial vault and the cranial fossae. A generalized Procrustes analysis was completed for the landmark sets. The coordinate locations describing the shape of each region were regressed with age to generate a model predicting the landmark location with age. Permutation testing was performed to assess significant changes with age. For the males, all anatomic regions reveal significant changes in shape with age except for the posterior cranial fossa. For the females, only the middle cranial fossa and anterior cranial fossa were found to change significantly in shape. Results of this study are important for understanding the adult skull and how shape changes may pertain to brain atrophy, aging, and injury.