About the vestibule
Vestibular medicine is an old and young discipline, especially in China, which has only developed to a certain extent in the last 20 years, and is still relatively unknown to many people in the medical profession. Although the vestibule is closely related to people’s life, work and even life activities, people, especially the general public, may rarely hear the word “vestibule”, so it is not surprising that people are often overwhelmed when faced with vertigo caused by the majority of vestibular system disorders in their lives. As the incidence of vertigo is increasing year by year, and the trend is younger, and our society is aging, it has become urgent to popularize the knowledge of vertigo and vestibular medicine to the public.
1.What is the vestibule of human body?
The vestibule is the main peripheral receptor organ of the human balance system and is located in the temporal bone of the skull. The human ear is divided into the outer ear, middle ear and inner ear (inner ear is also known as the “labyrinth”), the vestibule is in the inner ear and is one of the inner ear organs, consisting of three semicircular canals, balloons and ellipsoidal sacs. It is closely connected to the cochlea and is collectively known as the locus coeruleus. The vestibular organ is small and complex, with curved hard tubes lined with hoses, and the semicircular canals and the balloons and ellipsoidal sacs are also filled with a fluid called endolymphatic fluid. The vestibular organ has a special anatomical structure and functional characteristics.
2. What are the functions of the vestibular receptors?
The vestibule and cochlea of the inner ear are collectively known as the locus coeruleus, which, as the name implies, is responsible for perceiving position and hearing; the vestibule perceives the spatial position of the body, and the latter is responsible for hearing. The vestibule perceives the angular acceleration of body rotation, while the balloon and ellipsoidal sacs perceive linear acceleration. For example, when sitting in a moving car, even if you close your eyes and do not look out of the window, you can sense the acceleration, deceleration or turning of the car; for example, when riding in an elevator, the sensation of ascending and descending is perceived by the semicircular canal and otolithic apparatus.
Vestibular receptors perceive the body’s position in space and its position changes, and these information to the central transmission, mainly produces two aspects of physiological effects: on the one hand, the body’s changing position and posture adjustment, to maintain the body’s balance; on the other hand, involved in the regulation of eye movements, so that the body in the body position change and movement to maintain clear vision, so it is important to maintain our posture balance and clear vision Therefore, it plays an important role in maintaining our postural balance and clear vision.
3.What is the relationship between vestibular and vertigo?
Vertigo is a motor or positional hallucination, which is a conflict between pathological, or physiological positional stimuli in the body and the higher sensory centers of the brain. Clinical vertigo is a manifestation of the dysfunction of the body’s balance system, including the patient’s own sensation of rotation or the sensation of rotation, swaying, floating, lifting and tilting of the surrounding scenery. The feeling of heavy head, drowsiness and fainting are not included in the category of vertigo.
The human balance system is also composed of receptors, afferent nerves, balance centers, efferent nerves and effectors. The vestibule of the inner ear is the main nerve endings receptor (followed by the visual and proprioceptive receptors) of the human balance system. Whenever the impulses from any one of the three receptors to the center are not coordinated with the impulses from the other two receptors, or when there is an asymmetry in the afferent information from the vestibule of the inner ear on both sides, vertigo and imbalance symptoms result. On the other hand, because the vestibular system of the inner ear is the main system for maintaining the balance of the body and is widely connected with other systems of the body, vertigo can be caused by its own disorders or by the disorders of other systems involving the vestibular system. Therefore, vertigo is mostly caused by the incoordination of the vestibular system in the inner ear, which accounts for about 70% of vertigo cases.
For a long time, the definition of vertigo in various disciplines and schools of medicine has been different, but in principle it is similar, namely: vertigo is a kind of motion hallucination caused by the body’s spatial orientation recognition disorder. During the attack of vertigo, the patient suddenly feels that he or she or the surrounding objects are rotating or swaying in a certain direction, and does not dare to open his or her eyes; he or she is unstable in walking or standing, leaning to one side and other balance disorders; it may be accompanied by different degrees of nausea, vomiting, pale face, cold sweat and other vegetative symptoms; at this time, the patient may also see both eyes jumping to the left or right in the horizontal direction, which is often referred to as nystagmus by doctors. This is called nystagmus.
On the other hand, vertigo is an extremely common sensation in humans, and it is not necessarily a medical condition that needs to be treated. In a broader sense, vertigo can be divided into pleasure vertigo and discomfort vertigo, and pleasure vertigo is mainly for healthy people, such as the effects of stimulating amusement activities (spinning airplanes, wooden horses, swinging boats, etc.), moderate drunkenness and taking certain “special drugs” for the sake of momentary vertigo; those caused by various pathological factors, which make patients feel uncomfortable. It is the vertigo caused by different pathological factors that makes the majority of patients feel uncomfortable that is the object of medical research, which is also the topic we want to talk about.
4.Is dizziness and vertigo the same thing?
Dizziness and vertigo are not the same thing. Although patients often mix the terms dizziness and vertigo to describe their conditions, medically the two are different. First of all, the causes are different: vertigo is mainly a specific symptom caused by the vestibular balance system of the inner ear and its related diseases, while dizziness and light-headedness caused by cerebrovascular, hypertension and other diseases are what makes dizziness dizzy. In addition, blackness in front of the eyes and dizziness caused by postural hypotension are not vertigo.
Secondly, there is a difference in the symptoms: vertigo is when the patient feels that the sky is spinning or spinning or tilting by itself, such as riding in a boat, and when the patient has the onset of vertigo, both eyes are closed tightly and both hands are holding the bed, fearing to fall off the bed, accompanied by nausea and vomiting, and in severe cases, vomiting bitter water, abdominal pain and diarrhea, pale face and cold sweat. Although the symptoms are serious, but the patient is conscious, some patients can also feel the surrounding scenery swinging from side to side, or floating up and down, the above symptoms are called vertigo, which is a symptom specific to inner ear-vestibular system diseases. Dizziness is a feeling of light-headedness when a patient has an attack. For example, the feeling of dizziness at the onset of hypertension, sleep deprivation and alcohol overdose should be called dizziness; and those who suddenly stand up after squatting or sitting for a long time and feel black eyes, golden eyes, unstable standing or sudden fall due to some causes of temporary loss of consciousness are not dizziness but syncope. Dizziness and syncope are caused by various diseases related to the central nervous system, and are essentially different from inner ear vertigo.
5.Why is it necessary to check vestibular function in vertigo? What are the tests related to vestibular function?
Because vertigo is mostly caused by lesions in the vestibular system of the inner ear, doctors often ask patients to undergo vestibular function tests first when they visit a clinic for vertigo in order to analyze and find the cause of vertigo and adopt an appropriate treatment plan.
The vestibular organ is small and complex, and it is located in the temporal bone of the skull, so it cannot be examined from the morphological point of view by visual, tactile, snap, auditory or ultrasonic means like the examination of the thoracic and abdominal organs, nor can it be examined from the electrophysiological point of view by tracing the changes of its potential through the electrodes attached to its body surface like the examination of the heart. In addition, the vestibular nervous system is widely connected with other systems in the body, so the detection of vestibular function is difficult, complex and special, and can only be detected indirectly through the vestibular response. Vestibular reactions include three parts: 1. sensory reactions (vertigo), 2. motor reactions (nystagmus, body tilting and overshooting), and 3. vegetative reactions (nausea, vomiting, sweating and pallor). Among them, vertigo is only a subjective sensation and cannot be analyzed objectively, while item 3 is an objective reaction but lacks objective analysis index. At present, only nystagmus and body tilting response can be objectively analyzed in clinical practice, and this is what is commonly used in clinical vertigo diagnosis, namely nystagmography and posturography (both static and dynamic). Nystagmography is a series of systematic tests, including many items such as spontaneous nystagmus test, visual motion, visual tracking test, rotation test, position test, temperature stimulation test and so on. This series of tests is tedious, time-consuming, and the equipment is expensive, and is usually performed only in large general hospitals or ENT hospitals.
In recent years, video nystagmography (VNG), vestibular autorotation test (VAT), video head impulse test (V-HIT), dynamic visual acuity test (DVA), subjective visual linear test, dynamic posturography and high-frequency rotation test have been popularly used in clinical practice. The techniques have been popularly used in clinical practice. The Department of Otolaryngology, Head and Neck Surgery of Tianjin First Central Hospital is equipped with internationally advanced and the most complete vestibular treatment equipment in China, which has greatly relieved the problem of vertigo patients’ difficulties in seeking medical treatment, and the passive state of “patients’ vertigo and doctors’ dizziness” has become a thing of the past.
Vestibular function tests are non-invasive and functional tests, which can objectively evaluate vestibular function in terms of vestibulo-ocular reflexes and vestibulospinal reflexes, and can clarify whether there are abnormalities or lesions in the vestibular system, the degree of lesions, the side of the damage, whether the lesions are central or peripheral, and perform localization, qualitative and quantitative analysis to help doctors diagnose, analyze the evolution of the disease, judge the stage of the disease and prognosis, etc., which are important for the diagnosis, differentiation and treatment of vertigo-related diseases. It is of great value for the diagnosis, differentiation and treatment of vertigo.
Of course, it is now possible to obtain tomographic images of the vestibular organs by CT or MRI. The study of vestibular brainstem or cortical evoked potentials has also made some progress, but it is still a long way from being widely used in clinical practice. Currently, only vestibular myogenic evoked potentials (VEMP) are being used in clinical balloon function assessment.
6.What is the relationship between VEMP and vestibular function?
Some doctors ask patients to test vestibular function, while some doctors or doctors from other hospitals ask to check Nystagmogram, posturography, ENG or PG, and patients are at a loss. In fact, this is just a conceptual issue. Vestibular function testing includes many items such as Nystagmography and Posturography, which means that Nystagmography and Posturography are done to check the status of vestibular function, and they are the same thing. Nystagmography and posturography are called Electronystagmography (ENG) and Posturography (PG) respectively, and are often abbreviated by clinicians.
7.What patients need vestibular function testing?
Statistics show that 70% of vertigo cases are caused by vestibular system disorders or diseases involving the vestibular system, so vertigo patients should first consider whether there is something wrong with the vestibular system and have vestibular function testing done to analyze the cause. In most hospitals, vestibular function testing is done in the Department of Otolaryngology, and in some hospitals, it is done in the Department of Neurology.
Since the vestibular center has a compensatory effect on vestibular injury, patients may not have vertigo symptoms when vestibular injury is slow and progressive, such as bitemporal auditory neuroma, cholesteatoma at the brainstem; and there may also be no obvious vertigo symptoms when there is bilateral vestibular injury, so those patients who have tinnitus + progressive hearing loss, trigeminal or glossopharyngeal neuralgia (caused by cholesteatoma compression), or balance disturbance in the dark should also undergo Vestibular function testing.
Various diseases with vertigo as the main symptom can be classified into vestibular and non-vestibular according to the location of the lesion, with the former being the most common, and it is divided into two types: vestibular peripheral and vestibular central. When vertigo is caused by the vestibular receptors and vestibular nerve in the inner ear, we call it periventricular vertigo. It is characterized by episodic, rotational vertigo, oscillating sensation, floating sensation, elevation sensation, etc. It also has horizontal or horizontal rotational eye tremor and vegetative reaction (nausea, vomiting, cold sweat, etc.) which are consistent with the degree of vertigo, and is often accompanied by tinnitus and hearing loss. During the attack, the patient is conscious and the symptoms last from a few minutes to a few days, usually relieved in a few hours, but rarely more than a week. Central vestibular vertigo is caused by lesions in the vestibular nucleus of the brainstem and the vestibular pathways above it, such as inadequate blood supply to the vertebrobasilar artery and brain tumors in the posterior cranial fossa, accounting for about 10%-20% of vertigo cases. It is mostly non-rotational vertigo with relatively mild degree, usually without nausea and vomiting or severe nausea and vomiting inconsistent with the degree of vertigo, and may be accompanied by impairment of consciousness and other signs of nerve injury, rarely with cochlear symptoms, with long duration and slow process. In contrast, non-vestibular vertigo is not difficult to distinguish because of the presence of obvious signs and symptoms of the primary disease. For example, cervical spondylosis, refractive error, abnormal blood pressure, etc.
If there is no comprehensive vertigo treatment center, different types of vertigo should be treated in corresponding departments in order to get reasonable treatment in a short time and save money.
8.What are the considerations for vestibular function tests?
Most of the series of vestibular function tests are evoked by giving appropriate stimulation (rotation, temperature change, position change, etc.) to vestibular end receptors, and the vestibular function is evaluated according to the strength, presence or absence of vestibular response (mainly nystagmus). Because some vertigo patients have sensitive vestibular state, the test may be accompanied by varying degrees of nausea or vomiting, so the vestibular test requires patients to fast in order to avoid vomiting during the test, which may interfere or affect the test. In addition, vestibular function is easily affected by excitation or inhibition of the higher centers of the brain, so stop taking central excitatory or inhibitory drugs, such as Valium and caffeine, at least 24 hours before the test. Coronary heart disease, severe hypertension, cardiac insufficiency, caution; if the elderly, it is best to have a family member accompany.
9, vestibular function test on the human body what harm?
As we are relatively new to vestibular function and its detection, some patients have some fear of vestibular testing, often reversing the consultation process, that is, should be the first to do vestibular testing to the last, often both delayed diagnosis and treatment, but also to increase the cost of the consultation. In fact, the vestibular test is a physiological, functional examination, although a few patients may have varying degrees of sweating, nausea and other discomfort during the test, but it does not have any damage to the human body, so the vestibular test is a non-invasive test.
10.Posture chart (PG) examination
Posturography ( PG ), also known as the human center of gravity balancing apparatus, is a qualitative and localized examination method for vertigo and balance dysfunction caused by lesions in the vestibular system, vision and proprioception, mainly through the vestibular-spinal reflex to detect the human balance adjustment ability and the functional state of the vestibular system. During the test, the subject stands on the balance table in Romberg posture, and the pressure sensor converts the changing center of gravity of the foot into an electrical signal, and the computer automatically records various parameters of the trajectory of the changing center of gravity, and then analyzes and evaluates them. It has the characteristics of short examination time, convenience, safety and non-invasive, without any external stimulation and discomfort. It is suitable for the initial examination and evaluation of the balance function status of various vertigo diseases and the dynamic observation of clinical treatment effect, such as inner ear vagus disease, vestibular neuritis, ototoxic drug poisoning, sudden deafness, pontocerebellar horn occupational lesion, vertebrobasilar artery blood supply deficiency, cerebral trauma, cerebrovascular accident, cerebellar ataxia and cerebellar spinal cord degeneration, etc. If combined with nystagmography G-vestibular function examination, it can better understand the degree of vestibular function damage and also the central compensation, which improves the diagnosis rate and is of great value to the diagnosis and prognosis assessment of vertigo patients. This device integrates detection, treatment and rehabilitation, and provides a new quantitative, intelligent and simple treatment method for clinical patients with various vertigo disorders and balance disorders, and also provides a new research method for scientific research of related disciplines.
Although DPG is more comprehensive and valuable for the overall analysis of balance function and weighting of various balance information as well as balance rehabilitation training, it is more commonly used in research institutions because of its expensive equipment, and has not yet been popularized to the treatment of vertigo and balance disorders among the general public.
11.What is vestibular rehabilitation? What measures are included?
With the change of medical model, the change of disease structure and the change of people’s understanding and requirements of health, the emergence and development of rehabilitation medicine has become a historical necessity in response to this change, and only rehabilitation medicine can take up the important mission of comprehensively improving the quality of life of the sick and disabled, and rehabilitation medicine has become an important branch of medicine alongside clinical medicine. Although the medical science of rehabilitation for the sick, injured and disabled started late in China, it has been developing vigorously since the 1980s, especially in recent years. Rehabilitation not only focuses on the disease itself, but also on the dysfunction caused by the disease, focusing on improving the quality of life and restoring the patient’s ability to live, learn and work independently.
Vestibular rehabilitation is one of the branches of rehabilitation medicine, and is only in its infancy in China because of its strong professionalism. To be precise, vestibular rehabilitation is the rehabilitation of human balance function after the injury of balance system (mainly including vestibular, proprioceptive, visual and cerebellar balance centers), and the essence of rehabilitation is to promote and establish balance function compensation, because vestibular is the main system to regulate human balance, so it is also called vestibular compensation.
Rehabilitation is not only the implementation of treatment, but also includes rehabilitation assessment and rehabilitation prevention. Rehabilitation assessment is the foundation of rehabilitation treatment. Without assessment, it is impossible to plan treatment and evaluate its effectiveness. Rehabilitation assessment is not about finding the cause and diagnosis of the disease, but about objectively assessing the nature, location, severity, developmental trend, prognosis and regression of functional impairment. The functional assessment related to rehabilitation treatment should be conducted before, during and after the rehabilitation treatment.
Vestibular balance rehabilitation includes both passive (training equipment such as rotating chairs and dynamic balance tables) and active rehabilitation (specific training conducted by patients under the guidance of physicians), and active rehabilitation training is the main focus. At present, some large general or specialized hospitals in China have started to carry out this work.