Introduction
The inner portion of the frontal bone has a benign overgrowth, which is a defining feature of hyperostosis frontalis interna. The cause is unidentified. The syndrome is typically accidental and has little clinical relevance. Usually bilateral and symmetrical, it may also affect the parietal bones. The bone may be affected in a concentrated or dispersed manner by the sessile or nodular thickening of the cranium. It reflects an anomaly of the frontal cranial bone that is characterized by bilateral, nodular thickening of its inner lamina and may occasionally be linked to neuropsychiatric symptoms like headaches and sadness. It is typically asymptomatic and is mostly encountered in postmenopausal women. Most typically, it is detected as an unanticipated finding during an X-ray or CT (computed tomography) scan of the skull.
What Is Hyperostosis Frontalis Interna?
The thickening of the skull's frontal bone is a defining feature of hyperostosis frontalis interna. The real rarity of this illness has yet to be entirely established. Some medical professionals think that up to 12 percent of females may have this prevalent condition. Seizures, headaches, obesity, diabetes insipidus, excessive hair growth, and problems with the sex glands are just a few of the ailments to which the disorder may be linked. Elevated serum calcium and alkaline phosphatase may also occur.
What Causes Hyperostosis Frontalis Interna?
Since the condition has been identified in several generations, it is possible that it is inherited as a dominant trait. It is unknown if the condition is X-linked or autosomal dominant. Male-to-male (father-to-son) transmission is not known to occur. The interaction of two genes, one inherited from the father and one from the mother, leads to the development of human features, including common genetic illnesses. One copy of the illness gene, inherited from either the mother or the father, will express itself in dominant diseases, "dominating" the other normal gene and causing the disease to manifest. Regardless of the sex of the kid, there is a 50 percent chance that the disorder will be passed from an affected parent to their offspring throughout each pregnancy.
What Are the Sign and Symptoms Associated With Hyperostosis Frontalis Interna?
1. Overgrowth or thickening of the frontal bone of the head is the main characteristic of hyperostosis frontalis interna. Only an x-ray can reveal this extra growth.
2. Other conditions that may be present in patients with this disorder include:
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A central nervous system disorder is marked by an abrupt, aimless, uncontrollable discharge of electrical energy in the brain, resulting in a convulsion or loss of consciousness.
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Disturbances of the ovaries and testes (sex glands or gonads), excessive body hair, and epilepsy.
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Obesity (excessive body fat is a disease that raises the chance of developing health issues).
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Virilization (in virilization, a woman exhibits traits linked to male hormones that androgens, or when a baby exhibits traits linked to exposure to male hormones at birth).
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Decreased vision.
How Does Hyperostosis Frontalis Interna Develop?
Estrogens trigger the major ossification centers on each frontal bone to begin again. However, it is generally known that the level of estrogen gradually declines until menopause after 25 years of relatively regular occurrence following menarche. Although the impact of leptin on bone metabolism is debatable, some studies contend the increased frequency of hyperostosis. Frontalis interna in the contemporary age is related to hormonal changes brought on by microevolutionary factors such as easier access to food and faster metabolic rates. It is thought that the occurrence of hyperostosis frontalis interna in some wealthy and well-fed ancient societies has led many academics to make the incorrect assumption that hyperostosis frontalis interna is a genetically transmitted condition among particular historical people.
Over the past few decades, there has been an increase in the consumption of dietary phytoestrogens from foods such as soy, wheat, linseed, and vegetables. These food items have the potential to influence estrogen metabolism and improve bone density both pre and post-menopause. The estrogenic action of these dietary sources is dose-dependent. Therefore in civilizations where phytoestrogen consumption is high, the frequency of hyperostosis frontalis interna may be higher than in societies where a more varied diet is practiced.
Why Does the Frontal Bone Get Affected in Hyperostosis Frontalis Interna?
The preferred hormone target is the frontal bone. The middle part of the frontal squama is typically where the hyperostosis frontalis interna process starts. The original centers of ossification of the bone are thought to be the location of origin. However, these areas continue to function bilaterally as adults. The major foci of ossification of the frontal bone may be reactivated by estrogen activation, leading to aberrant bone development. The bilaterality of hyperostosis frontalis interna further supports the ossification center involvement, and the hyperostosis is restricted to regions connected to the ossification centers and excludes both the midline area (metopic suture) and bregmatic area (anterior fontanel).
The frontal bone might be more prominent because of its unique vascularization. It is stated that hyperostosis frontalis interna is usually noticed around a depression that could have vascular openings. The grooves between the bony ridges of hyperostosis frontalis interna are occupied by veins exiting the diploe, and the diploic venous system of the frontal bone is independent of those (parietal and occipital) draining other calvarial bones. The dura's attachment to the inner surface of the frontal bone is another distinctive feature of this structure.
Conclusion
A rare condition called hyperostosis frontalis interna (HFI), that is more prevalent in postmenopausal women, causes the frontal bone's volume and porosity to rise. It could be symptomatic or asymptomatic, depending on the size. Other factors that might be important include the female gender, advanced age, prolonged estrogen stimulation, and high leptin levels. Although it can extend as far as the anterior parietal and temporal bones, the thickness is often limited to the frontal bone. Especially in postmenopausal females, hyperostosis frontalis interna (HFI) is frequently discovered during autopsy and radiological imaging. Hyperostosis frontalis interna has no known treatment. Standard drugs can be used to treat headaches and seizures. Patients and their families may benefit from genetic counseling. Other forms of treatment are supportive and symptomatic. To know more about this condition, consult the doctor online.
