otosclerosis
Introduction
Introduction to otosclerosis Otosclerosis is a disease of unknown cause. Pathologically, it is due to the primary localized bone resorption of bone labyrinth, and it is called "hardening" on behalf of the vascular-rich spongy bone hyperplasia. When invading the egg garden window, it can cause the humerus to be fixed, lose the sound transmission function, and make the hearing progressively decline. The incidence of otosclerosis has a lot to do with human races. The incidence of whites is high, the incidence of blacks is the lowest, and the yellows are somewhere in between. The age of onset is more and more young and middle-aged. Surgical treatment is the most effective measure to improve hearing. The short-term curative effect of patella sacral surgery is better, but the hardening source can not be controlled, and the long-term curative effect is poor. It has been rarely used. Inner ear fenestration can also improve hearing, but the long-term effect is poor, and there may be sensory hearing loss. At present, it is generally used that part or all of the humerus is removed, and then the artificial humerus is installed. The operation under the microscope requires certain equipment conditions and technical levels. basic knowledge The proportion of illness: 0.001% Susceptible people: no special people Mode of infection: non-infectious Complications: tympanosclerosis
Cause
Etiology of otosclerosis
Genetic factors (40%):
In recent years, many scholars believe that ear sclerosis is an autosomal dominant genetic disease. Clinical epidemiological investigations suggest that the occurrence of this disease does not depend on simple dominant and low-expression genes, but mainly related to a rare dominant gene with multiple genetic components, gene expression is affected by age, gender, The effects of factors such as hormones vary. An otosclerosis gene is currently known, located in the autosomal 15q25-q26 segment, with a multi-point linkage analysis with a linkage value of 3.4. Further linkage analysis localizes it between the far central centromere (FES) and the near centromeric locus (D15S657), ie, a 14.5 cm (centimorgan) fragment of the long arm of chromosome 15 may contain an otosclerosis gene.
Racial factors (20%):
The incidence of otosclerosis has a lot to do with human races. The incidence of whites is high, the incidence of blacks is the lowest, and the yellows are somewhere in between. The age of onset is more and more young and middle-aged.
Other factors (30%):
The nutritional disorders and endocrine effects of the lost bone shell may be related factors for the occurrence of this disease.
Pathological process
Histopathological changes may involve the epithelial layer, endogenous cartilage layer and endosteal layer of the bone labyrinth. The pathological process has three main characteristics: 1 focal absorption and destruction of bone: microvascular dilation of the bone labyrinth, increased blood vessels Osteoclasts are active and repeated focal destruction and absorption of bone mass. 2 Spongy-like bone tissue formation: the bone marrow gap is enlarged, the bone is reduced, and a spongy new bone is formed. 3 Osteoporosis and osteosclerosis: the vascular space is reduced, the bone is calm, and the fibrils are woven, forming a dense, hardened bone. The pathological process of otosclerosis does not develop in a certain order, and the above three main features can occur alternately in one lesion simultaneously or repeatedly.
Prevention
Ear sclerosis prevention
1. Young people can't be too much, too long to listen to MP3, etc. Excessive use of headphones can also cause chronic damage to hearing. If you really need to keep using your headphones, take a break every half an hour.
2. It should be avoided to use aminoglycosides (such as streptomycin, gentamicin and kanamycin) for newborns and children.
3. Couples with childbearing risks should receive genetic guidance and prenatal counseling.
4. Ear trauma and infection should be prevented.
5. Should prevent colds.
6. Care should be taken to avoid possible causes of deafness, such as: staying up late or feeling exhausted and mentally stressed, you should pay attention to adjustment and rest.
7. Chronic otitis media should be treated as soon as possible to avoid the continued development of deafness.
Complication
Otosclerosis complications Complications tympanosclerosis
Most causes of death are still complications caused by serious illness, such as sepsis, aspiration pneumonia, hemorrhoids and so on. Only a small number of patients die from cardiovascular and respiratory effects due to inflammation of the brain stem life center.
Symptom
Otosclerosis symptoms common symptoms tinnitus vertigo deafness
1. Deafness: Progressive hearing loss in both ears or in a single ear is the main symptom of this disease.
2. Tinnitus: About 20%-80% of patients have tinnitus. Tinnitus is mostly low-frequency, persistent or intermittent, and high-frequency tinnitus can occur in the later stage.
3. Webster's misunderstanding phenomenon: patients in the general environment to distinguish the difficulty of speech, in the noisy environment, the ability to listen to improve, this phenomenon is called Wei's misunderstanding.
4. Dizziness: A small number of patients have a brief mild vertigo during head movements.
Examine
Examination of otosclerosis
1. Clinical examination of the external auditory canal is more wide, the tympanic membrane is normal, and the activity is good. Sometimes in the upper quadrant of the tympanic membrane, the area where the periosteum of the tympanic membrane is significantly congested and reddened. This phenomenon is called Schwartze's sign (Schwartze'ssign) and is one of the characteristics of clinical otosclerosis.
2. Audiological examination
(1) Tuning fork test: Rinne test 256Hz negative, 512Hz positive indicates early hearing damage, 256Hz, 512Hz are negative, indicating hearing damage is aggravated; Weber test is biased to the disease side or heavier side of the deafness; Schwabach test bone extension is extended; Gelle test is negative It may suggest that the sacral floor is hardened and fixed, which is of great significance for the diagnosis of this disease.
(2) pure tone audiometry: the bone conduction hearing curve can be reduced in the "V" shape in the 1000Hz or 2000Hz area, called the Carhart's notch, suggesting that the humerus floor is fixed, which is also one of the characteristics of otosclerosis. The hearing curve varies depending on the degree of fixation of the tibia and the extent of the lesion. The early stage is conductive sputum, the middle stage is mixed sputum, and the late stage is mixed sputum or sensorineural hearing loss.
(3) Acoustic impedance test: Ascus type curve As, normal, amplitude decreased or biphasic curve, the sacral muscle reflex threshold increased or disappeared.
(4) Otoacoustic emission examination: DPOAE amplitude is reduced or no reflection is induced.
(5) Auditory brainstem response audiometry: I wave, V wave latency or threshold increase.
3. Imaging examination of the humeral X-ray film without middle ear mastoid lesions, CT scan and MRI can observe the vestibular window, round window, bone labyrinth and the auditory wall of the auditory canal.
Diagnosis
Diagnosis and diagnosis of otosclerosis
Diagnose based on
1. The cause is unclear. Progressive hearing loss with tinnitus. It occurs mostly in adolescence, first on one side and worsened during pregnancy. There may be Wei's misunderstanding and mild dizziness. There is often a family history.
2. Check: The tympanic membrane is thin or normal, can be SchwArtze sign (transparent red sign), the eustachian tube is smooth.
3. In the early stage, the hearing curve was mainly low frequency, the mid-term curve was flat, the bone conduction curve had CArhArt notch (Y notch), and the late stage was mixed . Gelle's test was negative.
4. The acoustic impedance measurement method shows that the sound is reduced, the drum curve is As-type, and the sacral muscle reflex disappears.
5. The mastoid X-ray film shows good gasification, and the X-ray multi-track tomographic film can show the hardening source of the bone labyrinth.
Bilateral asymmetric conduction sputum that slowly occurs, gradually worsens, or sensorineural hearing loss that is incompatible with age, with symptoms such as low-pitched tinnitus, Willis auditory inversion, and dizziness, if there is a positive family history, Ear hardening should be considered.
Comprehensive analysis of medical history, family history, main symptoms, clinical signs and audiological examination results, typical cases can be diagnosed.
Differential diagnosis
The treatment of humeral ear sclerosis should be differentiated from middle ear lesions such as ossicular chain interruption, congenital ossicular chain fixation or malformation, adhesive otitis media, secretory otitis media, and tympanosclerosis without tympanic membrane perforation. Cochlear auricular sclerosis needs to be differentiated from acoustic neuropathy caused by acoustic neuroma, Meniere's disease and other causes.
