Hearing impairment has been studied by specialists in the field of health and education for a very long time, and it covers various aspects, such as: the anatomy of hearing and its physiology, the gift of speech, communication, and many others. Deaf people and those with hearing problems know how this failure affects human behavior.
In fact, the auditory ability of the ear is its secondary function. And the balance and balance of a person is precisely under the responsibility of this body. The vestibular system controls the sense of balance, which is so important for the spatial relationship between the body and the environment. Thus, it is necessary that vision, proprioceptive sensitivity and the vestibular system remain in perfect integration. No matter what and how we do, we do not need to worry about maintaining our balance, which is fully automatic.
Human equilibrium is a complex of motor activity, which includes sensory sensitivity of body movement, the transmission of motor-sensory information to the central nervous system and the implementation of appropriate responses of the musculoskeletal system. The vestibular system captures the visual axis through eye movements and helps to avoid image retention on the retina.
Vestibulometry - methods for studying the vestibular apparatus, allowing to judge its functions. The results of vestibulometry are assessed by the nature of nystagmus, that is, involuntary oscillatory eye movements, and autonomic reactions. These procedures are based on the ability of the system to somehow respond to external factors.
Vestibulometry is a rather informative diagnostic test, which is widely used in the presence of pathologies of ENT organs. In addition, it can be prescribed for diseases of the spine and neurological disorders. Vestibular testing consists of a series of tests that help determine that something is wrong with the vestibular (balance) part of the inner ear. These tests can help to avoid the most common complaint, such as dizziness, they will help determine the cause that the doctor can cure.
Why vestibular tests are needed
Maintaining the balance of the body during movement of the body and head depends on the harmonious interaction of sensory systems and the precise processing of information. For this reason, the central nervous system (CNS) constantly needs information from the vestibular, visual and proprioceptive systems about what is happening in the environment. This is in order to maintain the body in the right direction and balance. If there is damage to one of these systems, there will be a mismatch of information leading to conflict, which can lead to symptoms of body imbalance, such as dizziness, which is defined as an erroneous sensation of movement of the body in the environment. There are various types of dizziness, which can be divided into rotational dizziness, known as ordinary dizziness and dizziness without rotation, characterized by instability, fluctuations, a feeling of falling, gait deviation.
The central nervous system processes this information, combining it and generating responses with reflexes that improve control of posture and orientation of the body in relation to space, allowing a person to perform daily actions. The most important reflexes are the vestibuloocular reflex and the vestibulospinal reflex. Accordingly, the first allows you to stabilize vision during the movement of the head, and the second controls the movement of the body for stability of the head and body in order to prevent falls.
Dizziness has a high prevalence among the entire population of the world. Many authors consider it the main complaint after 65 years, present in approximately 80% of the population. As for the origin, in 85% of cases it is located in the vestibular system, and the remaining 15% come exclusively from ocular, neurological, psychiatric, metabolic and cardiovascular origin.
Indications for vestibulometry
With any suspicion of diseases of the vestibular apparatus, the ENT doctor prescribes vestibulometry, namely when:
- nausea, vomiting of central origin;
- violation of coordination of movement and unsteadiness of gait;
- fainting conditions;
- hearing loss;
- instability during movement;
- frequent darkening and flickering of flies before the eyes.
In this case, these symptoms can be observed periodically for no particular known reason or be constantly inherent in the patient's life. Such a symptomatology is often caused by another disease, lack of sleep, constant overwork or a trip by transport.
Mandatory indications for the study are:
- vestibular neuronitis;
- brain damage and condition after injuries;
- perilymphatic fistula;
- Meniere's disease;
- bilateral vestibular insufficiency;
- tumor neoplasms of the brain;
- multiple sclerosis;
- cerebellar ataxia.
Diagnosis of spontaneous vestibular reactions
The most common spontaneous vestibular reactions are nystagmus, impaired coordination of gait and movements, and shakiness in the Romberg position. These spontaneous reactions are those moments that manifest themselves in the absence of external influences. They can develop in any pathological process and have the form of involuntary motor reactions and autonomic disorders.
For example, to identify spontaneous nystagmus, the doctor suggests that the patient fix his gaze on any object in the hands of the doctor. Then you need to observe only with your eyes the movements of the hand, without turning the head. In the presence of vestibular nystagmus, the patient will experience two speeds of movement of the eyeballs. In one direction they will move slowly, in the other way very quickly.
There are also various manifestations and directions of nystagmus.
To investigate the coordination of movement of the upper extremities, an index and finger test have long been used. An indicative test is performed when the patient sits level. His hands are on his knees. Then the doctor puts his index fingers over the patient’s hands and asks him to touch the doctor’s fingers with his index fingers. The test is carried out first with eyes open, then with eyes closed.
With a finger test, the patient is asked to spread his arms in two directions, close his eyes, then, in turn, the person should touch the index fingers of both hands directly to the tip of the nose. If the left parts of the labyrinth are affected, then the patient misses to the right with one and the other hand, and exactly the opposite.
Stability in the Romberg position is a study of a person's static balance. In this case, the patient needs to become even, close his heels and socks together, put forward two outstretched arms and spread his fingers. Repeat also with open and closed eyes, like those of the above tests.
Also, for the examination of patients with vestibular pathologies, tests based on walking are used. This is important for assessing dynamic equilibrium, the ability to maintain an adequate body position during movement.
There are several varieties of this procedure, each of which is characterized by certain features. The basis of these techniques is the process of stimulation of the vestibular receptors. It is they who help the doctor to make the correct diagnosis and determine further treatment tactics:
- Caloric test - slow infusion of water with a Jeanne syringe into the ear canal (water temperature 40 degrees or more often cold - 18 degrees). Accordingly, they can carry out both thermal and cold calorization. To evaluate the sample, you need to determine the time of completion of the procedure until the onset of nystagmus. Normally, the time is from 25 to 30 seconds. The duration of the nystagmus itself is also determined. Normal for healthy patients is from 50 to 70 seconds. When perforating the eardrum, a caloric test is not recommended.
- The purpose of testing the swivel chair is to determine whether dizziness may occur due to a violation of the inner ear or brain. The rotational test is carried out in a special swivel chair. The patient stays upright, his eyes are closed, his head is tilted down, his legs are on a stand, and his hands are on the armrests. 10 uniform rotations to the right, then to the left are carried out. Rotation speed - 1 revolution for 2 seconds. After stopping the chair, a person will try to focus his gaze. You need to start counting the time. The doctor should determine the duration, severity of nystagmus. Normally, nystagmus lasts about 30 seconds. Lengthening the time of nystagmus indicates an increase, a decrease - with a partial or complete suppression of the excitability of the labyrinth.
- Pressor test or pistol symptom thickens (or vacuums) the air in the ear canal using a rubber bulb, or a special cylinder. The resulting nystagmus indicates the presence of fistulas in the lunar channel: with thickening of the air, nystagmus occurs - a positive test. As a rule, it is positive in chronic protracted inflammatory processes in the middle ear.
- Wojciech otolithic reaction is carried out on a rotating chair. The patient tilts his head 90 degrees and closes his eyes. Then do 5 rotations for 10 seconds. Then a 5-second pause and the patient is offered to raise his head and open his eyes. A pronounced deviation of the body and autonomic symptoms (nausea, cold sweat, dizziness and others) indicate an increase in vestibular-vegetative sensitivity. The reaction of the otolith apparatus is carried out as professional selection at work, where it is necessary to maintain balance in difficult conditions.
- When stabilometry objectively assess the static equilibrium. This method is highly sensitive and helps to identify vestibular pathologies at the earliest stages. Sometimes, the patient may not have any complaints. The person under investigation is placed on the platform and the computer registers each oscillation of the center of gravity of the body in various planes. Later, the computer processes the information and provides the results of the study.
Since each ear has 5 individual motion sensors, and most of the tests described above relate to only one of them (side semicircular canal), there is obviously enough space for new tests. Theoretically, 4/5 of the inner ear can be destroyed, but traditional vestibular testing may not even detect this.
Given the first tests of vertical semicircular canals, little progress has been made over the past 20 years. In fact, this is due to the fact that no one has developed a practical way to stimulate individual vertical semicircular canals (the caloric test does this for the lateral semicircular canal). Tests for swivel chairs are the closest, but at best they stimulate two vertical channels on opposite sides of the head.
Finally, the entire vestibular nerve can be tested using galvanic stimulation. This is an old technique in which electric current is transmitted to the ear and eye movements or postural effects are recorded. This technology is currently not commercial and quite limited, because it is difficult to pass enough current into the ear without causing pain. However, the test may increase in use when a vestibular prosthesis is available to replace the vestibular system in individuals who have had severe bilateral vestibular loss.
Preparation for vestibulometry
3 days before vestibulometry it is forbidden to drink alcohol or take narcotic, sedative and psychotropic drugs. If you need to take such medications for medical reasons, you must definitely inform your doctor. Also, prior to vestibulometry, cosmetics such as eye shadow and mascara are prohibited. They can make it difficult to record eye movements.
How is vestibulometry
During vestibulometry, the patient must follow with his own eyes the target, which is moving. In this case, with the help of infrared cameras, all eye movements are recorded, mounted in special large glasses that a person puts on before the procedure. All moments are recorded in detail and read by a computer. This is what helps doctors to get a complete picture of the structure of the vestibular apparatus and its work. In this case, the reaction rate and the accuracy of eye movements are evaluated. Then the doctor conducts other vestibular tests.
Contraindications to the study
It is contraindicated to perform vestibular tests, especially rotational manipulations, for intracranial hypertension, in the acute period with traumatic brain injury and acute cerebrovascular accident, during severe cardiovascular diseases.
Treatment and prevention of vestibular disorders
Advances in our understanding of vestibular physiology and its changes in various diseases have established that of the three therapeutic approaches to treating disorders of the vestibular system, namely, pharmacotherapy, surgery, and physiotherapy, the latter, that is, physical therapy, is most effective in managing balance disorders. The failure of the use of vestibular sedatives to correct vestibular disorders and correct the balance is currently recognized. Also a very limited role in this surgery. The development of vestibulometry now allows you to localize any lesion in the vestibular system with extreme accuracy, as well as determine the exact cause of the balance disorder. Thus, treatment methods, especially with physiotherapy, should be specific to the organ and, if possible, also specific to the disease itself.
To avoid diseases of the vestibular apparatus, you need to think about your health in a timely manner. Namely: to lead an active lifestyle, eat right, monitor the prevention of arterial hypertension and atherosclerosis, cervical osteochondrosis, follow all the doctor’s recommendations. For the vestibular apparatus it is useful to do gymnastics, skating, cross-country skiing. Aerobics is no less useful in this regard. Particularly effective exercises using fitball.
It can be concluded that vestibulometry is an effective technique for detecting violations of the vestibular apparatus in the early stages, determining their nature and possible causes. It helps the doctor determine further treatment tactics and the need for other diagnostic methods.