Benign tumor of the neurinoma of the auditory nerve does not represent a threat to human life, but significantly reduces the quality of existence in the field of perception of sound information. Usually neurinoma tumor is formed on the basis of nerve fiber cells, which are concentrated in the area of the vestibular part of the auditory nerve.
To understand the mechanism of development of neurinoma, it is necessary to have an idea of the structure of the auditory nerve. This is the radicular tissue, which provides a nerve impulse from the labyrinth of the ear to the structures of the brain. Two anatomical parts of this formation are distinguished. One of them is responsible for the balance of the balance of the human body, the second ensures the transmission of the sound wave. The vestibular part is divided into two zones, which form a balance. These are the lower and upper components of the auditory nerve.
Affects the disease equally in men and women. In childhood, almost never occurs. The bulk of diagnosed cases of neurinoma tumor development occur at the age of 40 to 45 years. Pathology for a long time develops without clinical symptoms and can manifest itself already at a late stage, when urgent surgical intervention is required.
Causes of neurinoma of the auditory nerve and the consequences of
Currently, the causes of neurinoma of the auditory nerve are not known to science, there are only presumptive theories. Among them, the most reliable is the viral hypothesis of the imbalance of cellular structures in the nerve fiber region of the auditory nerve. Among other causes of neurinoma of the auditory nerve, physicians refer to head trauma, vascular pathology, inflammatory processes in the middle ear cavity and its labyrinth.
The effects of the neurinoma of the auditory nerve largely depend on the stage of development of the tumor. The larger the size of the neoplasm, the more serious the clinical picture and the more dangerous the consequences of this pathology.
Consequences of neurinoma of the first stage of development are not significant and can only provide short-term difficulties in moving a person in space. There are regular dizziness and violations of the vestibular function. Symptoms of seasickness may occur when moving by car. Gradually, deafness develops, which at first is manifested by deafness.
In the second stage, the tumor can reach up to 2 cm in diameter and exerts considerable pressure not only on the auditory nerve, but also on the surrounding brain tissue. The consequences of neurinoma at this stage may consist of severe headaches, a retinitis in the ears, a sharp decrease in hearing, a distortion of the facial mimicry. There may be light paresis of the facial musculature, distortion of taste sensations.
Consequences of neurinoma in a sharp violation of vestibular coordination, which are accompanied by sudden falls, unsteadiness of the gait and nystagmus of the eyeballs, appear in the third stage of growth of a benign neoplasm. Tumors of neurinoma can reach in this case 7 cm in diameter. There are deviations of the mental state of a person, strabismus in the direction opposite to the location of the neurinoma.
The effects of neurinoma can only be removed by surgical removal of the tumor. After a successful operation, all functions are restored in full. Relapse of the disease is possible only if there is a genetic provocative factor.
Symptoms of neurinoma of the auditory nerve
Most often the symptoms of neurinoma at an early stage do not have a pronounced clinical manifestation. It can be a periodic dizziness and a sudden loss of a sense of balance. Hearing loss develops gradually as the growth grows. Hearing loss is not a determining factor in diagnosing a brain tumor. It is necessary to exclude organic lesions of the tympanic membrane and the labyrinth of the inner ear.
The most dangerous symptoms of neurinoma are given in the case of its close location relative to the brainstem. It is here that the centers that control respiratory activity and regulate the heart rate. In the case of compression of the neurinoma of the brain stem, a stop of breathing and heart can come, which threatens the life of a person.
Clinically pronounced symptoms of the auditory nerve neurinoma are usually diagnosed after 5 to 7 years from the onset of growth of the neoplasm. All this time a person can feel completely healthy. As practice shows, surgical treatment is required only in the late stages, when symptoms of compression of the brain structures appear. In the early stages of development, the tactics of managing such patients is the regular examination and comparison of clinical results. Approximately half of patients have a tumor stopping at early stages of development and until the end of a person's life does not show any signs.
In many ways, the symptoms of the neurinoma of the auditory nerve depend on the place in which it develops. The closer the neoplasm is to the brain stem, the higher the likelihood of an unfavorable development of pathology. With dimensions that do not reach 20 mm in diameter, there are no clinical manifestations in any case. To reveal a tumor neurinom in this case it is possible only by means of methods of special diagnostics.
In the vast majority of patients, the first symptoms of neurinoma are various hearing impairments. It can be unpleasant noise, ringing, stunning. These phenomena can be one-sided or symmetrical depending on the local nature of the tumor process. Two-sided noise in the ears indicates a symmetrical development of neurinoma.
Another group of symptoms is a consequence of disruption of the vestibular apparatus. They include dizziness( sometimes even when sitting), nausea, weakness, discoordination of movements. Orthostatic dizziness may occur: weakness and instability occur with a sharp ascent to the legs from the position, sitting or lying down.
Diagnosis of acoustic neurinoma
Modern diagnostics of the neurinoma of the auditory nerve can detect pathology even at the earliest stages. Initially, an examination with an otolaryngologist is conducted to determine the level of hearing loss and perception of sound. Specialists can be assigned audiograms and auditory tests. To clarify the location and size of the tumor, the most effective are such types of examination as computed tomography and magnetic resonance imaging of the brain. In the absence of the possibility of conducting such studies, the doctor may confine himself to the radiography of the cranium with the use of a contrast agent. In some cases, an electroencephalogram may be required, on which one can see a disturbance in the process of the impulse from the auditory nerve to the structures of the cerebral cortex.
The purpose of neurinoma diagnosis of the auditory nerve is to determine the stage of the pathological process and to make a decision about the need for surgical treatment to remove the tumor.
Treatment of neurinoma of the auditory nerve: removal and postoperative period
At small sizes, radiosurgery can be used as a method of treatment without opening the skull. This is the most sparing way to get rid of the existing problem. Radiation therapy can inhibit the growth of the neoplasm and lay the vector of its reverse development.
The removal of neurinoma is a surgical intervention under general anesthesia. Removal of tumor cells with complete or partial preservation of the auditory nerve substance is performed. In most cases, successful removal of neurinoma leads to a complete restoration of hearing and viability of the vestibular apparatus.
Postoperative period with neurinoma of the auditory nerve is divided into early, recovery and rehabilitation. In the early period it is important to restore all vital functions of the human body, to prevent the development of a secondary meningic infection. In the late recovery and rehabilitation postoperative periods after the removal of neurinoma, a regular examination is necessary to avoid recurrence of the disease. Rehabilitation measures aimed at restoring hearing and mobility of facial musculature are carried out.