Frontal bone hyperostosis: what is it, causes, symptoms, treatment

What is Frontal Hyperostosis?

Frontal hyperostosis - This disease is characterized by a thickening of the frontal bone of the skull. It is not clear how common the disorder actually is. Some doctors believe the disorder may be a common disorder, found in 12 percent of the female population. This disorder can be associated with various conditions such as epilepsy, headaches, obesity, diabetes insipidus, excessive hair growth, and gonadal disorders. Patients may also have an increase in serum alkaline phosphatase and an increase in serum calcium.

Signs and symptoms

The main feature of frontal hyperostosis is excessive growth or thickening of the frontal bone of the head. This excess growth can only be seen on an X-ray. As a result, scientists believe the condition may be much more common than previously thought, but often goes unnoticed. Many people have no overt symptoms of the disorder.

Other conditions that can be found in patients with this disorder include:

• obesity, a condition in which a woman acquires secondary male sexual characteristics (virilization);
• a disorder of the central nervous system characterized by sudden, aimless, uncontrolled seizures or loss of consciousness (epilepsy);
• decreased vision;
• headaches;
• disorders of the ovaries and testes (gonads);
• excessive body hair growth;
• diabetes.

Causes and risk factors

Frontal bone hyperostosis has been found over many generations, suggesting that the disease may be inherited as a dominant trait. It is not known whether the disorder is autosomal dominant or X-linked. There are no known cases of transmission from father to son.

Human traits, including classic genetic diseases, are the product of the interaction of two genes, one from the father and the other from the mother.

In dominant disorders, one copy of the disease gene (obtained from the mother or father) will be expressed as "dominant" over another normal gene and lead to the appearance of the disease. The risk of transmission of the disorder from the affected parent to the offspring is 50 percent with every pregnancy, regardless of the sex of the child.

Affected populations

Frontal hyperostosis affects women 9 times more often than men. This disorder is most common in middle-aged and older people, but it also occurs in adolescents.

Symptomatic disorders

Symptoms of the following disorders may be similar to those of hyperostosis of the frontal bone. Comparisons can be useful for differential diagnosis:

• Acromegaly is a slowly progressive chronic metabolic disorder in which excess growth hormone causes abnormal enlargement of various body tissues and unusual growth. The limbs, jaws and face are most noticeably affected. Enlargement of soft tissues, especially of the heart, is a serious feature of this disorder. High blood pressure (arterial hypertension) can be another serious consequence of acromegaly.
• Paget's disease Is a slowly progressive disease of the skeletal system, characterized by abnormally rapid destruction and formation of bone, which leads to the development of dense but fragile bones. This disorder usually affects middle-aged and older people and most often occurs in the spine, skull, pelvis, thighs, and legs. When the pathological process occurs in the skull, it can lead to hearing loss.
• Virchow's disease - This is a disease in which there is an excessive growth of the bones of the face, and sometimes the skull. This disease causes a general expansion and distortion of all features.

The following abnormalities have been found in connection with frontal hyperostosis. They are not needed for differential diagnosis:

• Cruson's disease Is a genetic disorder characterized by abnormalities of the skull, face and brain caused by the premature hardening of the skull. The skull consists of several plates of bone, initially connected by fibrous connective tissue, which usually grows together and hardens within a few years after brain growth. In Crouzon disease, facial deformities are often present at birth and may progress over time. In some cases, visual impairment and deafness may develop.
• Galactorrhea - This is a condition in which there is a spontaneous outflow of milk from the nipple.
• Myotonic dystrophy Is an inherited disorder that affects muscles, vision and endocrine glands. Myotonic dystrophy can cause mental deficiency and hair loss. The onset of this disorder usually occurs at a young age, although it can occur at any age and varies greatly in severity. Symptoms of this disorder may include stumbling, falling, difficulty moving the neck, or lack of facial expressions.
• Diabetes insipidus caused by an abnormality of the antidiuretic hormone (vasopresin or ADH) that occurs in the posterior lobe of the pituitary gland. Lack of this hormone in the kidneys causes an excessive amount of very dilute (but otherwise normal) urine to be excreted. Excessive thirst is the main symptom of this disorder.

Standard treatments

There are no known treatments for frontal hyperostosis. Attacks and headaches can be treated with standard medications.

Genetic counseling can be beneficial for patients and their families. Other treatments are symptomatic and supportive.

Lilia Khabibulina/ article author