Cause of sudden hearing loss
introduction
The main cause of impaired hearing due to sudden hearing loss is suspected to be a circulatory disorder of the blood in the inner ear with accompanying insufficient supply of the hair cells. The hair cells represent the sensory cells of the inner ear, which are responsible for converting the sound stimulus into an electrical stimulus.
The impulses are then passed on from the hair cells via the auditory nerve to the brain, where the sound and tone can then be perceived as. In order to be able to maintain the function of the hair cells, it is absolutely necessary that these cells are supplied with blood and thus with oxygen. If there is a blood circulation disorder in the area of the inner ear, there is a loss of function with the hearing disorders described.
causes
The reasons why there is a circulatory disorder in this clinical picture have not been proven, but there are many causes for an insufficient supply of blood to the inner ear. To be mentioned are:
Vascular occlusions
Does the blood change its flow habits (viscosity), it can clot more quickly in the blood vessel with accompanying occlusion (embolism) of the vessel. The prerequisite is that the flow rate of the blood is reduced. This happens when the blood becomes thicker, e.g. is the case with reduced daily fluid intake. Older people are also particularly at risk here. Blood clotting disorders can also lead to premature blood clotting and thus cause vascular occlusion. It is assumed that the Sudden hearing loss a little stroke or infarction of the inner ear is. The causes roughly correspond to those of a heart attack or a major stroke. Patients who suffer from the typical symptoms of a stroke (dizziness, Possibly. a headache, Paralysis etc.), often show a diminished Hearing ability on one or both ears. It is assumed that in addition to the blood clot that blocks a vessel in the brain, a small clot also obstructs the vessels of the inner ear. Also the one causing the heart attack arteriosclerosis, i.e. the thickening of the vessel wall due to fats and non-degradable glycerides, is held responsible for the cause of a sudden hearing loss. This can be caused by a permanently high cholesterol level, lack of exercise, Obesity or Diabetes mellitus occurrence.
noise
Noise can also be a possible cause of sudden hearing loss. The underlying mechanisms, however, have not yet been precisely clarified.
One explanation lies in the direct effect of noise on the inner ear. In order for us to be able to hear, hair cells in the inner ear have to be deflected to different degrees depending on the pitch and volume. This can be visualized as a lawn on which the blades of grass are deflected by the wind. Will the Hair cells constantly distracted by noise, their metabolism increases and they need more nutrients and oxygen. If the noise persists for a longer period of time without a break for regeneration, the metabolism will eventually be exhausted and the hair cells can no longer be adequately supplied. The consequence is that irreparable loss of hair cells. As the decline progresses, hearing performance eventually declines.
Another explanation is the psychological distress from noise in the foreground. If the person concerned cannot escape the noise, he perceives it as stress. It tenses automatically and reactively it comes to Release of hormonesthat to one increased blood pressure through a narrowing of blood vessels. Usually, this response from the body makes a lot of sense, as stress requires a willingness to act. However, if the blood pressure rises too much, the blood flow may be impaired in some cases. One possibility is that the vessels leading to the inner ear are becoming too narrow. The consequence is one Undersupply of the inner earwhich manifests itself in a ringing in the ears or hearing loss. If this condition lasts too long, it can lead to sudden hearing loss with further symptoms.
stress
Although there is no evidence for this either, stress always becomes an accomplice Sudden hearing loss given. This is probably due to the fact that hearing loss often occurs in patients who are either in an acutely stressful situation or who suffer from a chronic stressful situation. One explanation is a high one Adrenaline rush during a stressful situation. adrenaline has the task of increasing the blood pressure accordingly (see also: high blood pressure). This is done by constricting the blood vessels. If the vessels constrict too much and reduce their diameter, the hair cells of the inner ear can also suffer from an insufficient blood supply (similar effect of Heart attack).
Injuries
Inner ear or hair cell damage can always be caused by injuries and trauma. It is therefore particularly important to ask the patient about recent falls or accidents.
Infections and Inflammatory Causes
Infections can also cause hearing loss. These infections can otherwise be inconspicuous and only affect the Inner ear to make noticable. Diagnosis is difficult because of this. Pathogens can Mumps viruses, Herpes viruses, HIV or be adenoviruses. The doctor should therefore ask the patient about the accompanying illness at the moment and the weeks and months beforehand when researching the cause.
A Otitis media (ottitis media) can also cause sudden hearing loss. The reason here is an inflammatory accumulation of fluid in the inner ear, which hinders the transmission of sound from the outside to the inside.
cold
A Cold can simulate sudden hearing loss. As a rule, however, there is no dysfunction of the inner ear. Only that Symptoms these mutually independent diseases can overlap. Both diseases can namely become one Feeling of pressure in the ear, dizziness and one Hearing loss to lead.
In contrast to sudden hearing loss, however, with the common cold no circulatory disorder in the inner ear. Rather, it is that Inflammatory swollen mucous membrane in the throat arealeading to a ventilation disorder of the middle ear. This in turn manifests itself in a feeling of pressure in the ear and a hearing loss. When you have a cold, dizziness is not caused by a functional impairment of the equilibrium organ in the inner ear, but rather by the paranasal sinuses, which are usually filled with secretion and exert a strong pressure on the structures of the skull.
Misalignments of the spine
In principle all vascular occlusive situations can unite Sudden hearing loss trigger. One shouldn't forget either Holding and growth damage of the Spine, especially the Cervical spinewhich, through corresponding bends, can squeeze vessels that supply the ear with blood and oxygen.
Malfunctions in the cervical spine itself can have various causes. One possibility would be muscular tension in the neck and neck areathat impair supply structures that pull from the back towards the ear. Hardened muscle parts can press on blood vessels or nerves and thus manipulate the supply of the inner ear, which can manifest itself symptomatically in a sudden hearing loss.
A direct injury to the inner ear is due to muscle tension unlikely, but by a Whiplash conceivable. A twisting of the cervical spine in the context of an accident can therefore be another possible cause.
If there is no acute accident and bony changes can still be found, this is the case age-related wear and tear to be seen as a possibility for a narrowing of blood vessels or nerve cords towards the ear. For the treating doctor, the description and posture of the patient are usually decisive, so that he can examine the cervical spine more closely as a possible cause of a sudden hearing loss. Gives the patient a unilateral Ear noise and shows abnormal posture or muscling in the neck region, the cervical spine is quickly revealed as the cause in most cases.
Autoimmune diseases
In principle, all autoimmune diseases that affect the blood vessels in the body can also cause sudden hearing loss. Here, too, the patient should be asked about typical accompanying signs of sudden hearing loss. A patient who e.g. at the so-called Temporal arteritis suffers, usually also complains of a strong, throbbing headache. The diagnosis is confirmed by a blood test and the identification of autoantibodies that can be found in the blood in such a case.
Tumor diseases
The possibility of a tumor in the area of the auditory nerve as a cause of hearing loss must always be considered. Although this is Cause of sudden hearing loss quite rare, but should not be ignored. In the case of a tumor, the so-called acoustic neuroma is the most common cause of hearing loss tumor described. The diagnostic method of choice here is magnetic resonance imaging (MRI) Of the head.
Neurological causes
At times it can happen that major neurological diseases can trigger the symptoms of a sudden hearing loss. In addition to the stroke described above, this should also be mentioned Multiple sclerosis (MS) and meningitis (meningitis).
Middle ear obstructive causes
In many cases, one side of the sudden hearing loss is simply due to ear contamination from increased lard production or improper cleaning with cotton swabs (The ear wax plug is pushed into the ear canal).
consequences
In the most cases there is a sudden hearing loss complete recovery. Very rarely does hearing loss or noise in the ears persist. However, it is increasing Risk of permanent damage with the Number of sudden hearing loss, because hair cells break with every sudden hearing loss.
Hair cells are essential for our hearing, so their dwindling number explains the intensification of symptoms. In simple terms, this means that the worse someone hears, the more hair cells they lose. A relapse is particularly favored by stress and cardiovascular diseases, which can impair the blood circulation in the inner ear.
