Neurofibromatosis is a group of hereditary diseases with characteristic changes on the skin, in the nervous system, often in combination with abnormalities in other organs and systems.
Currently, there are 6 types of neurofibromatosis, of which the most important are neurofibromatosis type I (Recklinghausen disease) and neurofibromatosis type II (neurofibromatosis with bilateral neuromas of the VIII pair of cranial nerves).
The disease is caused by a mutation of the “nf1” gene on the 17q chromosome.
Men and women are affected equally often.
About half of the cases are due to new mutations. There is an assumption that the gene “nf1” is included in the group of genes that suppress the growth of tumors. The decrease or absence of the protein neurofibromin, the production of which is controlled by the nf1 gene, leads to cell degeneration.
Manifestations of neurofibromatosis type I
Diagnostic criteria (for the diagnosis, you must have at least two criteria):
- 6 or more spots on the skin of “coffee with milk”, each in diameter more than 5 mm in a child and more than 15 mm in an adult;
- 2 or more neurofibromas (any) or 1 plexiform neurofibroma;
- enhanced color in the axillary and inguinal areas;
- optic nerve glioma;
- 2 or more Lisha nodules – colored iris hamartomas;
- Pronounced bone abnormalities in the form of dysplasia of the main bone, thinning of the cortical layer of long bones with or without pseudoarthrosis;
- The closest relative to the diagnosed neurofibromatosis type I (mother, father, brother, sister, child).
In patients with type I neurofibromatosis, an increased risk of developing malignant tumors is observed: neuroblastomas, gangliogliomas, sarcomas, leukemias, Wilms tumors.
The peculiarity of the disease is the specific sequence of symptoms depending on the patient’s age, which makes it difficult to diagnose type I neurofibromatosis in early childhood. From birth or the first years of life, there may be only some signs of neurofibromatosis type I (large pigment spots, plexiform neurofibromas, skeletal lesions). Other symptoms may appear much later (by 5–15 years).
Neurofibromas are the most pronounced manifestation of Recklinghausen’s disease, their number sometimes reaching several thousand; Plexiform neurofibromas can be gigantic, weighing more than 10 kg. These cosmetic defects, as a rule, most of all disturb patients. In addition, neurofibromas are associated with an increased risk of transformation into a malignant tumor. When placed in the chest, in the abdominal cavity, in the orbit, they lead to dysfunction of the adjacent organs.
From time to time, the number and size of neurofibromas in response to various stimuli, among which the leading place is occupied by: hormonal changes in the body, adolescence, pregnancy period or after childbirth, as well as trauma or serious illness. Very often, surgical interventions, certain cosmetic procedures, physiotherapeutic procedures (for example, massage, warming) contribute to the growth of neurofibromas. But often the disease progresses against the background of apparent well-being.
Manifestations of neurofibromatosis type II
- bilateral neuromas of the VIII pair of cranial nerves (according to tomography)
- the closest relative with diagnosed neurofibromatosis type II (mother, father, brother, sister, child), in combination with:
- unilateral neuroma of the eighth pair of cranial nerves
2 signs from listed below:
- glioma (astrocytoma, ependymoma)
- schwannoma (incl. spinal)
- juvenile posterior subcapsular cataract .
Concomitant manifestations of type II neurofibromatosis (but not diagnostic criteria): epileptic seizures, skin manifestations (“coffee with milk” spots, skin neurofibromas), multiple spinal tumors (ependymoma, schwannoma, meningioma).
The Central Healthcare Institute of the Ministry of Health of the Russian Federation proposed the following treatment regimen for neurofibromatosis type I: ketotifen is prescribed in 2-4 mg short courses for two months. To avoid complications, in the first two weeks of taking the drug, it is recommended to use phencarol in parallel, 10–25 mg three times a day.
As a drug that reduces the rate of cell division, tigazon is used in a dose of at least 1 mg per kilogram of body weight or aevit to 600,000 IU, taking into account tolerability. Also courses use lidaza (mucopolysaccharidase) at a dose of 32–64 U, depending on the age intramuscularly, every other day, for a course of 30 injections