According to WHO statistics, acoustic neuroma is diagnosed on average in one person for every 100,000 examined. This pathology occupies about 12% of all brain tumors. This disease occurs both in young patients and in elderly people, but recently this disease has been increasingly diagnosed in people from 30 to 40 years old. In addition, it has been noted that neuroma almost never occurs in children, but women are diagnosed three times more often than men.
What is this
Neurinomas are tumors of the auditory nerve, which are benign neoplasms formed from the cells of the Schwann sheath. That is why their second name is schwannomas. Despite the specific name, this pathology does not affect the auditory nerve, which consists of a pair of roots with different physiological purposes: the cochlear nerve is responsible for transmitting auditory signals to the brain, and the vestibular nerve is responsible for the sense of balance. It is in the tissues of the vestibular root that schwannoma is formed.
According to medical reports, acoustic neuromas have the appearance of a densenodular formation with a bumpy surface. Sometimes in the tissues of such a formation there are small cystic cavities with fluid inside.
Despite the fact that neurinomas develop slowly and do not spread to neighboring organs, the appearance of these pathologies can significantly worsen the quality of life and the patient's condition. They lead to hearing loss and impaired functioning of the vestibular apparatus. Very often, this disease affects the facial (trigeminal) nerve.
Although acoustic neuromas are not cancerous, they can pose a risk to human he alth. Increasing to a large size, one or several neoplasms at once begin to put pressure on the brain stem. As a result, the patient begins to feel constant headaches (in extremely rare cases, disturbances in the clarity of consciousness are possible).
Reasons for appearance
The exact causes of the development of this pathology have not yet been established, as well as the factors affecting the development of acoustic neuroma. However, according to many researchers, one of the causes of the tumor is a genetic predisposition.
Risk factors
The only scientifically substantiated risk factor experts call a genetically determined pathology - type II neurofibromatosis. For this disease, the formation of benign tumor processes in various tissues of the nervous system is typical (for example, the appearance of neurofibromas, gliomas, meningiomas or neurinomas).
Morphologyneuromas
Macroscopically, an acoustic neuroma looks like a rounded or irregularly shaped nodular formation with a bumpy surface. Outside, it is covered with connective tissue, and inside, cystic formations filled with a brownish liquid are often found. The color on the cut is determined by the quality of the blood supply: under normal conditions - pale pink, with congestion - bluish, with hemorrhages in the tissue of the formed node - brown.
When microscopically examined, it consists of cells whose nuclei are similar in shape to rods. With the growth of a neuroma, fibrosis and hemosiderin deposits are observed inside it.
Acoustic neuroma symptoms
The development of this disease can occur according to different scenarios. In some cases, the tumor develops up to one and a half centimeters in diameter, but at the same time does not prevent a person from living a familiar life. With such a course of the disease, the removal of the acoustic neuroma is not required: here it is enough to control its condition by visiting a specialist once a year.
In other cases, the tumor increases significantly and begins to affect the auditory nerve root or even the brain stem. In this case, the following changes occur in the patient's body:
- gradual or sudden hearing loss in one ear;
- ringing in the ear (tinnitus);
- feeling stuffy in the ear;
- balance problems begin (unstability and dizziness);
- there is a feelingnumbness and tingling on the face (from the side of the affected area);
- in severe cases, paralysis of the facial or abducens nerve may occur;
- visual disturbances may begin, as well as difficulty in chewing food and swallowing it;
- dull or aching headache (usually seen in advanced stages of neuroma).
With these symptoms of acoustic neuroma, treatment is often a life-saving step, but many people mistakenly associate them with age-related changes and ignore these manifestations.
Over time, schwannomas that increase in size lead to a complete loss of the functions of the auditory nerve from the side of the lesion and disorders of the vestibular apparatus.
In addition, irreversible manifestations of a cut of the facial (trigeminal) nerve are possible. The pains accompanying this process eventually become permanent. In some cases, the patient takes them for a toothache. However, as the neoplasm grows in the tissues of the vestibular root, peripheral lesions of the trigeminal and abducens nerves occur, manifested as:
- paresis of the muscles involved in facial expressions;
- facial asymmetries;
- strabismus;
- loss of taste and other symptoms.
Pathogenesis of neoplasm
Specialists distinguish three stages of the tumor process occurring in the tissues of the vestibular root:
- Initial stage. The diameter of the neoplasm does not exceed 2.0 cm. At the same time, the patient notes hearing and vestibular disorders.device. There may be mild damage to the facial nerve.
- Second stage. Education becomes larger and reaches the size of a walnut. Clinical manifestations of neurinoma become more pronounced: hearing and coordination disorders become more serious, severe headaches are added. Sometimes these symptoms are accompanied by nausea and vomiting.
- The last stage. The tumor reaches the size of a chicken egg. Due to pressure on the brain or its trunk, there is a compression of its cerebral structures, hydrocephalus and visual impairment. Such changes lead to irreversible consequences in the brain, so the operation to remove the acoustic neuroma at this stage is impossible. For this reason, advanced forms of the disease are fatal.
Diagnosis of disease
An otoneurologist can diagnose this disease. In some situations, additional consultations of a vestibulologist, ophthalmologist and dentist may be required. The patient is scheduled for a neurological examination, audiometry, otoscopy, electrocochleography, electronystagmography, auditory EAP study, vestibulometry and stabilography.
More accurate diagnosis of a neoplasm can be provided by radiography and neuroimaging techniques. Acoustic neuroma is difficult to diagnose even with the help of computed tomography (CT), so the patient undergoes an x-ray of the skull with a targeted image of the temporal region of the head. If the picture clearly shows the expansioninternal auditory canal, this indicates the formation of a tumor. Schwannomas are detected when the disease is diagnosed using MRI (magnetic resonance imaging).
Treatment of acoustic neuroma
Today, there are two methods of radical treatment of schwannoma - surgery and radiosurgical methods. In addition, sometimes it is advisable to use radiation therapy. The choice of one or another method of influence is determined in each case individually and depends on:
- neoplasm size;
- patient's age category;
- general condition of the patient;
- hearing level;
- patient preferences.
If the symptoms of acoustic neuroma do not cause much concern to the patient (the tumor is small and does not compress nearby nerves), expectant management is chosen. The operation may also be abandoned due to the weakening of the patient's body or advanced age. In this case, the doctor recommends an annual follow-up and an MRI study.
Surgical interventions
Removal of acoustic neuroma is a very complicated operation. It is carried out only for young people, when the neoplasm increases in size and at the same time worries the patient.
Such surgical interventions are performed under general anesthesia, while it involves a craniotomy. Such operations can be performed in various ways: through the mastoid process (translabyrinthine path), behind the ear (retrosigmoid path) orthrough a trepanation above the ear (through the middle fossa).
The recovery period after acoustic neuroma surgery is a long process that requires regular medical supervision and takes from 6 to 12 months.
Radiosurgery
Stereotactic radiosurgery techniques are possible to remove relatively small schwannomas that do not exceed 2.5-3 cm in diameter. However, such procedures do not always give the expected therapeutic effect. Radiosurgical operations are performed to preserve the activity of the organs of vision, hearing and facial nerve. Typically, stereotactic radiosurgery is prescribed for older people with a protracted course after subtotal surgical interventions in cases where the risks of resections are much greater due to somatic pathologies.
Radiotherapy: Gamma Knife
This technique is a bloodless (non-invasive) technique for the treatment of acoustic neuroma. Its goal is to stop the tumor with minimal risk of damage to neighboring neural structures. The effectiveness of this method is based on the destruction of tumor DNA and blockage of blood vessels that feed the neoplasm.
This operation is indicated for patients with small schwannomas, the size of which does not exceed 3 cm in diameter, as well as for those with residual and recurrent phenomena after resections.
The advantages of this technique are that such point irradiation allows you to save the functions of the facial nerve (in 95% of cases) and the hearing organs (in 79%). After the procedure, there are never complications associated with open interventions (for example, meningitis or liquorrhea).
This procedure is performed in one session and the next day the patient can return to normal life.
Radiosurgery: Cyberknife
The use of this technique has no restrictions on the size of neoplasms, although the principle of using a cyber-knife is similar to the previous method of irradiation. After using this technique, patients no longer experience tumor growth in 95% of cases.
Expectant tactics
While the size of the neoplasm is small or if the tumor is localized in areas that do not affect the compression of nearby nerves, expectant treatment is recommended. No therapeutic measures are taken also in cases where surgical intervention is not possible due to the advanced age of the patient or the general weakness of the body.
In this case, the patient should regularly visit a medical institution to control the size of the neoplasm and receive symptomatic treatment in case of manifestations of the clinical picture of the disease.
Forecast
The outcome of acoustic neuroma is largely determined by the timeliness of contacting a specialist to diagnose the disease. A favorable prognosis for the course and treatment of this pathology can be said with adequate therapy of schwannomas in the first or second stages. With stereotactic radiosurgical interventions at the initial stages of developmentneuromas in 90% of cases, there is a cessation of the development of the neoplasm and a complete recovery of the patient. Surgical interventions have a high percentage of loss of hearing and function of the facial nerve.
At the last stage of acoustic neuroma, the prognosis is unfavorable: due to compression of the vital cerebral structures of the brain, a fatal outcome is possible.
