BAEP is a procedure in which the functioning of auditory pathways in the brainstem and the brain is tested by stimulating the auditory nerve.
A sound stimulus (click sound) 60-70 dB above the hearing threshold is given from a special earphone placed in the ear. The responses that occur when this stimulus reaches the auditory center in the brain through the anatomical connection points in the ear, auditory nerve, and brainstem are recorded with the help of electrodes placed on special points on the scalp.
The proper functioning of the system can be objectively tested over the waves recorded in accordance with the anatomical location of the regions where the sound stimulus should be transmitted. The patient doesn’t need to be compliant or even conscious during the procedure. It can also be applied to pregnant women, people with pacemakers, and small children.
It is used in the diagnosis of all neurological diseases that affect the auditory pathways and brainstem, especially multiple sclerosis (MS) and auditory nerve tumors. It is also used in the early diagnosis of hearing problems in infants, in the determination of the level of damage of the patient in a coma, and in the diagnosis of brain death for organ transplantation.
It is also very valuable in terms of revealing the loss of function that cannot be shown by MRI or not noticed by the patient.
As in every test, it should be performed and interpreted by experienced neurologists.
What is the BAEP Test?
BAEP; is a test that indicates the condition of the auditory nerves branching from the ear to the brain, the nerves related to the hearing function in the brainstem, and the hearing function of the brainstem.
The BAEP test can easily detect diseases by examining every instant of the hearing event from the degree of hearing loss in the patient and the anatomical structure through which the hearing cannot be transmitted to the brain to why there is no response from the brain to the auditory stimulus.
For this reason, when doctors need various audio tests, especially if they suspect an anatomical problem, they will definitely put you through the BAEP test.
How is the BAEP Test Performed?
During the application of the BAEP test, a specially produced earphone is placed in the patient’s ear. Electrodes are placed in certain places on the scalp. The electrodes are at least 2, at most 6, consisting of small sterile needles. During the positioning of the electrodes, the patient feels a small amount of pain that is milder than a normal needle stick. However, the test does not hurt, and there is no pain sensation during the procedure.
Afterward, the patient is given a warning sound with an intensity of over 60 – 70 decibels.
The transmission of this stimulus from the ear to the brain is recorded.
With the electrodes placed on the scalp, the response from the brain is also recorded.
It is examined whether there is a difference between the response that the patient should give and the response given to the warning sound, and according to the observed difference, in which part of the nerves and due to what kind of problem arises the hearing loss, along with the degree of hearing loss, can be determined.
It is not important whether the patient is asleep or not during the procedure. The procedure can be performed in cases where the patient’s consciousness is open or closed. Even when patients are unconscious, they give the same response to the sound stimulus as they do when they are conscious. The physician can look at the presence of any problem in both ways.
During the application of the BAEP test, the responses of the auditory nerves are examined one by one using 5 different sound wavelengths. In this way, a more objective finding is obtained.
In Which Diseases Is BAEP Test Required?
The BAEP test is applied when it is suspected that the problems in hearing are of neurological origin.
The application of the BAEP test is ordered by the physician in case the patient applies the physician with B12 deficiency, detection or suspicion of tumor in the auditory nerves, history of MS disease, as well as auditory problems.
It is a test that contributes to early diagnosis when hearing problems develop in both adult and infant patients.
Since it is not mandatory for the patient to be conscious during the procedure, the BAEP test is applied in order to detect damage in coma patients and to document brain death definitively in patients whose organs are donated.
The BAEP test can be easily applied during pregnancy, in people at risk of pregnancy, small children, unconscious patients, and infants. The application of the procedure and the interpretation of the results should be carried out by a specialist physician.