What is the main reason for numbness

Deafness can have many causes. We present the most common causes here.

 

 

Conductive disturbance

Sound conduction means that the sound passes through the outer ear, i.e. the auricle and the ear canal, the eardrum and the Ossicular chain is passed on to the inner ear in the middle ear. In the case of a sound conduction disorder, the fault is to be found in this chain on the way to the inner ear. A conductive disorder is often the cause of hearing loss, but rarely the sole cause of deafness. Because even if the transmission of the sound is severely disturbed, sound can still pass through the bones (Bone conduction) are perceived.

Sensory sensation disorder

In the case of sensorineural disorders, the focus of the disturbance is in the inner ear. The incoming sound is up to Cochlea forwarded, but then cannot or only partially be registered as a signal due to defective hair cells.

The severity of the hearing loss depends on the strength of the signal that is passed on to the auditory nerve. A low strength or the complete absence of the transmission is the cause of this hearing damage, whereas a relatively high signal strength causes a slight hearing impairment. The sensorineural sensation disorder can be congenital or caused later in life.

 

Psychogenic hearing disorder

In very rare cases, mental illness can also be the cause of deafness. This can lead to impaired hearing even if there is no evidence of damage to the ear. However, with special objective examinations it can be determined whether acoustic signals arrive in the brain.

Congenital deafness

If deafness is common in a family, it could be a sign of genetic hearing impairment. This can be caused by malformations in the inner ear or the brain. Trisomy 21 For example, it can be responsible for genetic deafness.

Furthermore, an unborn child can sometimes experience impairment or impaired hearing if the mother suffers from infections during pregnancy. The most common infections for deafness in the unborn child

  • rubella

  • Cytomegaly

  • Toxoplasmosis

  • syphilis

The consumption of certain ototoxic ingredients of drugs such as thalidomite as well as aminoglycosides contained in antibiotics or even drugs such as alcohol or nicotine during pregnancy can also cause hearing damage in the unborn child. If there is a lack of oxygen or cerebral hemorrhage during childbirth, this can also be a cause of congenital deafness. Premature babies, who often have immature lungs, or newborns who have been in the incubator for more than two days, suffer from a lack of oxygen shortly after birth, which increases the risk of hearing impairment.

Acquired deafness

A severe or prolonged infection of the ear is often a cause of loss of hearing. Both the middle ear and the inner ear can be seriously damaged. Meningitis, also called meningitis, and encephalitis, an infection of the brain, can also cause numbness. Meningitis can ossify the cochlea, whereas encephalitis damages the nerve pathways responsible for transmitting information in the brain.

Furthermore, even taking medication can be the cause of severe hearing impairment. Because some cancer drugs, certain dehydrating agents, some antibiotics, but also pain relievers and fever killers can have an ototoxic effect.

Even certain tumors, such as acoustic neuroma, can be a cause of hearing loss. Here, the benign tumor displaces the auditory nerve in its bony canal, causing disruptions or interruptions in the transmission of signals between the inner ear and the brain.

Finally, exposure to noise, circulatory disorders, sudden hearing loss or chronic diseases such as otosclerosis can all lead to acquired deafness. Industrial pollutants such as carbon monoxide and injuries, on the other hand, are less likely to cause deafness.

Symptoms

Signs of bilateral deafness (deafness) are complete or almost complete loss of hearing. If you are deaf on both sides, you can no longer perceive tones and noises and accordingly no longer react to acoustic stimuli.

If deafness is congenital, accompanying symptoms often occur in the form of damage to other organs such as eyes, kidneys, bones and skin. In order to receive adequate support despite the enormous hearing impairment, one should already pay attention to how babies react to acoustic stimuli.

In contrast, one-sided deafness is not that limiting as the healthy ear largely compensates for the hearing loss, which makes it harder to compensate for this one-sided hearing loss.

diagnosis

In order to diagnose a hearing loss, one-sided deafness or complete deafness, the following examinations are carried out:

  • Objective hearing test (BERA): This test method, which is particularly suitable for babies and small children, examines the functionality of the auditory nerve

  • Measurement otoacoustic emissions (OAE): With this procedure one tries to prove damage to the outer hair cells of the inner ear - balance test: With a balance test one would like to exclude a participation of the balance organ

  • Computed Tomography (CT) or magnetic resonance imaging (MRI): Imaging methods are used to rule out an anatomical change in the cochlea or the auditory nerve as the cause of the deafness

  • Promotional test: If a cochlear implant is intended for treatment, this test procedure is used to check the functionality of the auditory nerve