I. Concept.
1, vertigo: It is a motion illusion of body spatial orientation, which is wrong to rotate, shake and tilt to foreign objects and oneself, and can coexist with nystagmus, balance disorder, nausea, vomiting, cold sweat, pale face and other vegetative symptoms. It is a kind of motor hallucination, which is often referred to as “spinning”; the etiology is due to vestibular nervous system lesions.
3, dizziness: often manifested as a persistent dullness of the mind and a sense of lack of clarity, accompanied by heavy head, dullness, headache, forgetfulness, weakness and other neurological or chronic somatic disease symptoms, aggravated by exertion. It is caused by neurasthenia or chronic somatic diseases, etc.
4, syncope: sudden, transient loss of consciousness, accompanied by fainting. Consciousness is restored within a short time after fainting, and there is usually no eye tremor. It is caused by multiple causes of transient low blood pressure, slow heartbeat, and transient cerebral ischemia.
II. Mechanisms of vertigo.
It is caused by lesions of the vestibular nervous system.
1. The vestibular nervous system includes: the terminal receptors of the vagus of the inner ear, the potbelly crest of the semicircular canal, the ellipsoidal sac, the balloon spot, the vestibular nerve and the vestibular nucleus.
2.The vestibular nervous system has six pathways: vestibulo-ocular pathway, vestibulospinal pathway, vestibular reticular pathway, vestibular cerebellar pathway, vestibular vegetative pathway and vestibular cortical pathway. The bilateral vestibular nervous system is coordinated and synchronized. If a lesion occurs on one side, it can cause vertigo.
Vestibulo-vegetative pathway, vestibular reticular pathway: vestibular nerve → reticular formation → vasomotor center of medullary reticular formation + dorsal nucleus of vagus nerve → causes vertigo, nausea, vomiting, cold sweat, pale face and other vegetative symptoms.
Vestibular oculomotor pathway: vestibular nucleus → medial longitudinal tract of brainstem → each oculomotor nucleus connection: oculomotor tremor appears in case of lesion.
Vestibulocerebellar pathway: vestibular nucleus → vestibulocerebellar tract → anterior horn of the spinal cord: ataxia, balance instability and muscle tone changes.
Vestibulospinal pathway: vestibular nucleus → lateral vestibulospinal tract → anterior horn of spinal cord
The main clinical manifestations include one or more of the following
1. Self-rotation, swaying, tilting and other errors
2.Nystagmus
3, nausea, vomiting, cold sweat, pale face and other vegetative symptoms
4.Balance instability and ataxia
5.Types of vertigo
(1) True vertigo (peripheral, vestibular peripheral): mostly accompanied by obvious nausea, vomiting and other vegetative symptoms; short duration, from tens of seconds to hours, rarely more than several days or weeks. Mostly seen in vestibular peripheral lesions.
(2) Pseudovertigo (central, cerebral): symptoms are mild, accompanied by obscure vegetative symptoms; duration is long, up to several months. Mostly seen in brain and eye disorders.
IV. Vestibular function test.
The vestibular nervous system is an important system for spatial orientation and balance maintenance, and its abnormal function is one of the important causes of vertigo. The examination and evaluation of vestibular function is an important tool to diagnose vertigo and evaluate the effect of treatment.
1.Vestibular oculomotor reflex: clinically common nystagmography (ENG) or video nystagmography (VNG) examines vestibular function by objectively quantifying the vestibular oculomotor reflex (VOR), but it mainly reflects the horizontal semicircular canal function, so it has some limitations to reflect vestibular function only by VOR.
2, postural stability test: including Romberg test, reinforced Romberg test (also known as Mann test), single foot upright test, etc. are also widely used in clinical practice, for these clinical tests, in addition to determining whether the patient has tilted, there are timing methods, that is, record the specific time the patient maintains upright in these balance tests.
(1) When the human body is in an upright static posture, the body actually keeps swaying around its own balance point despite maintaining immobility, which is beyond self-conscious control and is called physiological postural swaying.
(2) The maintenance of postural balance relies on the synergy of vestibular, visual and proprioceptive systems. The visual system stabilizes the visual environment; the proprioceptive system provides information on muscle tone and the relationship between various body parts by receptors such as muscle shuttle, joints and tendons to maintain joint position and muscle tone; the vestibular system senses the static position of the head and linear acceleration by the balloon and ellipsoid bursa, and the angular acceleration by the jugular crest. The various information is integrated by a complex mechanism of the central system and innervates the trunk extremity muscles through the lateral vestibulospinal tract, called the vestibulospinal reflex (VSR); while the downstream fibers of the medial vestibulospinal tract transmit tension impulses affecting the vagus to the cervical muscles, called the vestibulocervical reflex. The final eye position maintains clear vision and regulates related skeletal muscle tone to maintain head position and correct posture.
The postural stability test is a test of the functional state of the human postural control system, which is a system of three inputs and one output. The three sensory inputs are vision, proprioception and vestibular sensation, and the output is body sway.
V: The causes of vertigo include
1.Otogenic (Meniere, vestibular neuritis, etc.)
2.Ocular origin
3, intracranial tumor, traumatic brain injury, cerebellar lesions (cerebellar stroke, thrombosis), insufficient blood supply to the vertebral basilar artery (TIA)
4, multiple sclerosis, cervical spine disorders, cervical spine whipping injury
5, motion sickness (motion sickness)
6, endocrine disorders (hypothyroidism)
7.Other
Six: Cervical vertigo
1. Definition: Cervical vertigo refers to the syndrome caused by cervical spondylosis, with vertigo and sympathetic symptoms as the main causes. Cervical spondylosis refers to cervical disc degeneration itself and its secondary changes that irritate or compress adjacent tissues and cause various symptoms and signs.
2. Mechanism: There are many theories about the pathogenesis of cervical vertigo at home and abroad, including four types
The theory of insufficient blood supply of vertebral artery
Sympathetic nerve theory
Cervical medullary injury theory
Proprioceptive theory
3.Diagnostic criteria.
(1) Symptoms of episodic vertebrobasilar insufficiency associated with head and neck activity: such as headache, dizziness, visual disturbance, tinnitus, and positive neck turn test.
(2) Neck symptoms: neck muscle spasm, stiffness and pain, limitation of movement, pressure pain, sometimes upper extremity numbness and pain, positive sign of pull test.
(3) With symptoms of autonomic dysfunction: nausea, vomiting, sweating, chest tightness, palpitations.
(4) In severe cases, there may be episodic sudden collapse, which usually occurs when the head is tilted back, lateral flexion or rotation. There is usually no loss of consciousness at the time of collapse, which is relieved by the change of position and with the reset of the neck position.
(5) Concomitant symptoms: A series of symptoms and signs of brainstem ischemia may be present at the same time.
(6) X-ray manifestations: asymmetry on both sides of the atlanto-axial and atlanto-dental joints, skewed vertebral spine, vertebral hyperplasia, narrowing of the vertebral space, deformation of the hook vertebral joint, calcification of ligaments, and formation of bone bridges are common.
VII. Comprehensive clinical examination of vertigo patients
If necessary, hearing examination, vestibular function examination, fundus examination, cerebrospinal fluid examination, cranial or cervical spine X-ray, electrocardiogram, electroencephalogram and cranial CT scan should be done to find out the cause of vertigo.
Physical examination: Before physical examination, emphasis should be placed on history taking. When the history is unclear, special attention should be paid to the patient’s vital signs, cardiovascular system, ear (including the outer, middle, or inner ear), and neurological examination.
Blood pressure. The presence of upright hypotension should be observed.
(ii) Note whether the patient has hyperventilation or a tense personality, as hyperventilation is usually associated with cardiac dizziness.
③Patients should be noted for arrhythmias and neck murmurs.
④Detailed hearing examination of the patient, noting the presence of otitis media and whether the hearing is normal.
⑤ Do a detailed neurological examination.
(6) When benign paroxysmal vertigo is suspected, the Dix-Hallpick maneuver can be performed by having the subject lie on his back with his head over the edge of the bed, keeping it 30° below the bed level and turning it 30° to 45° to the left or right, and then having the subject sit up and ask him to turn his head to the side and look at his forehead. The test taker holds the subject’s head with both hands, pushes back and quickly changes the subject from a sitting position to the above mentioned position. There is a resting period before the subject responds, sometimes up to 5-6 s. If the response is positive, the subject becomes dizzy, closes his eyes, screams, and tries to sit up. The subject should be reassured and remain in this position. The subject will also experience rotational nystagmus (lasting 2-10 s), which is directed toward the side of the lower ear. The symptoms may then slowly decrease. However, when the subject sits up, dizziness and nystagmus (in the opposite direction) may also occur. Repeated examinations may cause fatigue.
(7) Dizziness and light-headedness after prolonged standing may be associated with cardiovascular disease.
(8) Visual acuity examination.
Laboratory tests
(1) Head imaging: MRI is better than computed tomography if needed. It can help to rule out the presence of lesions in the anterior cranial fossa (MRI is more sensitive to small lesions in the anterior cranial fossa).
Biochemical tests, including hypoglycemia, hypothyroidism, anemia, renal failure, and vitamin B12 deficiency, may be the cause of dizziness.
Electrooculography can help determine the presence of vestibular lesions, especially in older patients.
Doppler ultrasonography of the basilar system of the neck can help to rule out subclavian artery steal syndrome and can also help us to distinguish whether vascular or osteoarthritic disease is the cause of neck vertigo.
(5) Electrocardiogram should be considered in case of arrhythmia.
(6) Cardiac ultrasound can be done for cardiac output deficiency caused by cardiovascular system problems.