How is the left ear often tinnitus?

Sudden tinnitus is obviously sudden, and tinnitus begins without any warning. Tinnitus occurs in an instant, or peaks within 48 hours at the longest. Sudden tinnitus mostly occurs in middle-aged people, with different degrees, and has occurred simultaneously with deafness. Tinnitus can weaken or disappear with the recovery of hearing. There are also tinnitus that disappears first, and then the hearing is restored or continues until the hearing is restored. Tinnitus is so serious that patients sometimes wake up when they sleep.

Pathogenesis (1) Virus infection

Virus infection is the most common cause of this disease. Virus infection follows the following main routes.

1. Blood-borne virus particles directly enter the blood circulation of the inner ear from the blood circulation, causing cochlear circulation disorder or endolymphatic labyrinthitis.

2. The virus invades the external lymphatic space from the subarachnoid space through the sieve plate at the bottom of the internal auditory canal or through the cochlear tubule to cause external lymphatic labyrinthitis, so cochlear symptoms appear after meningitis. Herpes zoster virus is the main pathogen causing lymphatic labyrinthitis.

3. Non-suppurative otitis media caused by the virus through the round window, and the infection can invade the inner ear through the round window.

(2) Vascular diseases

Vascular diseases are of great significance in the pathogenesis of sudden deafness. Wilson pointed out that the incidence of sudden deafness caused by partial or total occlusion of cochlear blood vessels is not clear, but it is less than viral labyrinthitis. Some people think that vascular diseases account for 3/4 of the causes of sudden deafness. Due to vascular disorders such as vascular compression, intravascular stenosis, bleeding, increased coagulation and fluctuation, the sensory structure of spiral organs is degenerated due to hypoxia. Among them, except those with vasospasm, the prognosis is poor, which often leads to permanent deafness.

Cochlear oxygen tolerance is very weak. After 60 seconds of hypoxia, cochlear microphonic potential and neural action potential disappeared. For example, if the blood flow is blocked for 30 minutes, although the blood flow is restored, the cochlear potential cannot be restored. With the help of a skin mucosa microscope with a magnification of 55 times, Okizaki observed the phenomenon of "congestion" of blood vessels in cases of sudden deafness, and thought that this phenomenon might cause microcirculation disturbance in the inner ear and lead to sudden deafness. Its pathophysiological mechanism is pathological blood coagulation → increase of blood viscosity → decrease of blood flow velocity → hypoxia → increase of permeability and tissue damage.