Deafness

Generality

The term "deafness" is often used in a generic way to indicate the total reduction or loss of hearing. This disorder can therefore have different degrees of severity; furthermore, it may depend on causes of different origin and nature.

• Hypoacusis, a term that indicates the partial or total impairment of hearing and whose intensity can be classified as mild, moderate, severe and profound.
• Cofosi, a term usually used to indicate a complete and bilateral loss of hearing, which can be congenital or acquired.

Deafness, therefore, is a pathological condition that can manifest itself already at birth, just as it can occur during the life of the individual following traumas, pathologies, etc.

Classification and Types of Deafness

The different forms of deafness can be classified according to different criteria.

In this regard, a first classification can be carried out according to the extent of hearing damage, distinguishing hearing impairment in: mild deafness, average deafness, medium-severe deafness, severe deafness and, finally, very serious deafness .

A further method of classification, which can be adopted, provides for the distinction of the various types of deafness according to the triggering cause (for example, traumatic, neoplastic, malformative, toxic, etc.); or depending on the location in which the injury occurred or in which there is the alteration responsible for the loss or reduction of hearing. In the latter case, we can distinguish:

• Deafness of the external ear;
• Deafness of the middle ear;
• Deafness of the inner ear;
• Deafness of the auditory nerve; etc.

Finally, another system used to classify the different types of deafness is that which is based on physiopathological criteria. In this case, therefore, we can distinguish:

• Transmission or transmission deafness, in which there is involvement of the external ear and / or the transmission structures of the middle ear, which do not conduct the sound correctly.
• Sensorineural deafness, in which the inner ear (cochlea) and / or acoustic nerves (including the central ones) are involved.
• Mixed deafness, in which the loss or reduction of hearing is caused by causes that act both at transmissive and neurosensory level.

To learn more, read: Ear: Anatomy and Functions »

Causes

As mentioned, the factors that can lead to the onset of deafness are manifold and of varied origin and nature, for example, traumas, pathologies, infections, etc.

However, among the main causes that can give rise to deafness, we remember:

• Malformations of the auricle, of the auditory canal or of other structures of the ear (external, middle or internal);
• Neoplastic diseases (benign or malignant tumors);
• Infections and inflammations of the middle ear and / or external ear (such as otitis), infectious diseases of the inner ear (such as meningitis or mumps) and auditory nerve (such as, for example, rubella or encephalitis);
• Perforation of the tympanic membrane;
• Acoustic trauma;
• Head trauma;
• Genetic factors that can lead to the onset of deafness at birth, or during the patient's life;
• Complications arising during pregnancy (such as, for example, contraction of particular types of infection by the mother) or complications arising during childbirth and which can lead to deafness in the newborn;
• Neurological disorders, such as multiple sclerosis or strokes;
• Ménière syndrome;
• Use of ototoxic drugs (such as, for example, aminoglycoside antibiotics, antimalarials and some types of anticancer drugs);
• Factors related to advancing age (presbycusis).

Signs and Symptoms

The signs and symptoms related to deafness may vary depending on the cause that caused it, as they may vary depending on whether it occurs at birth or during the life of the individual. Furthermore, the loss or otherwise the reduction of hearing not necessarily occurs in a sudden manner, on the contrary it can manifest itself gradually, thus giving rise to a symptomatology that can vary over time with the aggravation of hearing impairment.

In any case, among the most common signs and symptoms associated with deafness, we find:

• Difficulty in following the speeches and difficulties in understanding all the words that are spoken;
• Perception of muffled or distant sounds;
• Difficulty perceiving sounds at low volume;
• Vertigo (very common in the case of deafness caused by specific diseases, as in the case of Ménière's syndrome);
• Tinnitus;
• Pressure in the ear.

Moreover, it is good to remember that people suffering from deafness can also face communication problems related to language, particularly when deafness is present from birth. In these cases of congenital deafness - due to the impossibility of acquiring the normal verbal patrimony during growth - the child may experience so-called deaf-mutism, although the language can be taught to him through specific techniques.

In any case, even in the case of acquired deafness - therefore, in the case of deafness that develops during the person's life - one can face the total or partial loss of the verbal assets already acquired.

Generally, the lack of acquisition or loss of verbal patrimony are phenomena associated with the complete and bilateral impairment of hearing, therefore, to that which in the medical field is defined as cofosis.

Diagnosis

To make the diagnosis of deafness, first of all, the doctor will have to evaluate all the symptoms presented by the patient; subsequently, it will attempt to identify the underlying cause of hearing impairment.

Precisely in this regard, it is very important that the doctor knows the medical history of the patient and his family (to assess the presence of any hereditary factors predisposing to hearing loss), just as it is necessary for him to be aware of any behavior he has taken by the patient (exposure to loud noises, intake of ototoxic drugs, etc.) that may have contributed to the occurrence of hearing loss or reduction.

The doctor can also perform an otoscopic examination to determine the possible presence of obstructions or abnormalities of the ear canal, and to detect the presence of any infections or inflammations.

After the preliminary evaluation, the doctor, if he deems it necessary, can invite the patient to make a specialist examination by an otolaryngologist, who will carry out specific tests to make a complete and correct diagnosis.

Treatment

The treatment that the doctor decides to undertake may vary according to the type of deafness the patient suffers and depending on the cause that triggered it. Therefore, the therapeutic strategy to be adopted will be established by the doctor on a strictly individual basis for each patient.

For example, if the patient suffers from a deafness of a transmissive type, it is possible to intervene in different ways on the external ear or on the middle ear (depending on where the problem is located), in an attempt to restore hearing ability (as happens, for example, in case of perforation of the tympanic membrane, on which surgery can be performed to restore its integrity).

Again, if deafness is caused by infections or inflammation, or by taking ototoxic drugs, the latter are treated or the drug in question is suspended, in the hope that the damage caused to the ear is not permanent and that auditory function can be restored.

On the contrary, in the case of sensorineural deafness, the treatment is not so simple. In fact, in these cases the impairment of auditory function is permanent. However, there are some therapeutic approaches that can help patients in these conditions improve their hearing and communication skills.

More specifically, patients with sensorineural deafness can use (with the advice of their doctor) to use:

• Hearing aids, special electronic devices equipped with a microphone capable of detecting sound, which is then amplified thanks to the presence of a special amplifier and sent to the ear via a loudspeaker.
• Cochlear implants . These particular implants are surgically inserted and are indicated in cases of severe deafness, both unilateral and bilateral. Unlike what happens with hearing aids - which simply "convey" the sound in the ear canal - cochlear implants are designed to perform the function of the part of the inner ear that is damaged, sending information directly to the cochlear nerve. However, these implants are only useful for patients with sensorineural deafness that does not involve the involvement of acoustic nerves which must, therefore, be functional.

Finally, a very important role in the treatment of deafness is also played by educational and social support and language training of the same patient.