Vestibular nerve damage

Introduction The function of the vestibular nerve is to reflect the balance of the body, including the head, the eyeball, the body, and the limbs, and adjust the body's response to various accelerations. The most common symptoms of vestibular nerve damage are dizziness and nystagmus. Dizziness is a feeling that a patient feels that the environment or itself is rotating or moving. Although the incidence of vertigo as the first symptom is higher, the actual vertigo is significantly less than the first symptom. Reported only 10% of patients with vestibular neurological symptoms, and 65% of cases in the history of vestibular involvement, some occurred a few years ago. Dizziness often occurs in a quiescent state, but some patients induce or aggravate when changing postures such as bending, sitting up, or turning the head. Symptoms can be alleviated in patients who take sedative drugs.

Cause

(1) Acute vestibular neuritis: 80% of patients have a sudden onset of dizziness after awakening in the respiratory or gastrointestinal tract, and reach a peak in a few hours, accompanied by nausea and vomiting, which lasts for several days, weeks, and then Gradually returned to normal. The elderly are slow to recover and can last for several months. More than one ear is sick, and occasionally two ears have been diagnosed. There is a spontaneous paralytic nystagmus to the healthy side, which can cause illness in a family of several people, and there is also a small epidemic in the group. No tinnitus or deafness in the disease period is characteristic.

(2) Chronic vestibular neuritis: Most of them are middle-aged and above, can have recurrent dizziness, the degree is light, and it is obvious when walking upright. It can last for several years, and nausea and vomiting are rare, often showing long-term instability.

an examination

Related inspection

Ocular electroencephalography, neurological examination, maxillofacial five-score CT examination

Commonly used vestibular function tests are:

1 Limb balance function check: refers to test, step test, closed eye upright test (high white test), toe joint test, center of gravity swing test, dynamic position electrogram check, etc. The above examination can roughly understand the degree of limb balance disorder and conduct a rough analysis of the lesion.

2 nystagmus examination: nystagmus is an irregular rhythmical movement of the eyeball. It consists of slow phase and fast phase. It often occurs when the vestibular organ is ill. Different types of nystagmus have important reference value for the diagnosis of lesion location. Including gaze astigmatism examination, spontaneous nystagmus examination, positional nystagmus examination, dislocation nystagometry and so on.

3 semi-regulatory function check: commonly used spin test, cold heat test, pupil test, etc., through the rotation, temperature, pressure, etc. to stimulate the inner ear vestibule, the hair cell cilia deflection, induced limb deflection and nystagmus, thereby achieving Determine the purpose of the vestibular function.

4 nystagmus: There is a resting potential between the cornea and the retina of the eyeball, a positive charge on the side of the cornea, and a negative charge on the side of the retina, called the corneal retinal potential. The eye movement can change this potential, and the magnitude of the potential change is proportional to the angle of the eyeball deviation. This change in potential can be recorded by the skin electrode around the eyelid. This weak current is amplified and transmitted to the recording device, and the nystagmus is recorded in the form of an image. The nystagmus not only quantifies the duration, frequency, amplitude, and slow phase velocity of nystagmus, but also records various other abnormal eye movements.

5 eye movement function check: The eye movement system that controls eye movement is closely related to the vestibular system to maintain body balance. Commonly used examination methods include eye distance obstacle test, eye tracking test, optokinetic nystagmus test, visual inhibition test, etc., which help to judge the balance function state.

Differential diagnosis

Differential diagnosis of vestibular nerve damage:

Impaired vestibular function: Aminoglycoside antibiotics damage the eighth cranial nerve. If it affects the vestibular function of the inner ear, a type of disease with vertigo can occur, often during or after drug withdrawal. . Similar to the category of "dizziness" in Chinese medicine.

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