Our ears play an important role in our daily lives. They help us orient ourselves in space, transmit information and enable us to communicate with others. In addition, the organ of balance is also located there. What examinations and tests can the ear, nose and throat (ENT) doctor perform if something is wrong with the ear? You can find out here.
Patient interview before ear examination
Main complaints that bring patients to an ear specialist are hearing loss, pain, ear running, ringing in the ears and dizziness. First, the doctor will inquire whether the symptoms have come on suddenly or gradually and affect one or both ears. It is also interesting for him to know whether other complaints or illnesses are present, whether certain medications are being taken, and whether the affected person has been exposed to loud noise in the past. Similar complaints in the family can also provide important clues as to the cause of the disease. Often, a tentative diagnosis is already made at this stage; further examinations are then used to refine the diagnosis and to draw up or check the treatment concept.
Basic diagnostics: basic examinations.
The physical examination is performed mainly on a sitting or standing patient. Externally visible signs of disease (inspection) include swelling behind the ear and nodules, scarring or crusting in the pinna. An important role is played by the examination of the external auditory canal and the eardrum with a funnel-shaped ear microscope (otoscopy). This involves looking for earwax and other secretions, skin condition and constrictions, as well as assessing the eardrum. The color, shape, surface condition and integrity of the eardrum provide important clues to certain diseases such as middle ear infections or ventilation disorders. The connection of the ears to the nasopharynx is assessed during a nasal endoscopy.
Functional tests of the ears
Various tests can be used to check how far you can hear, which sounds are perceived and how well, and how sound conduction works in the ear. Important functional tests used to examine the ears include:
- Tuning fork tests
- Audiometry
Tuning fork tests
Hearing can be roughly checked with a tuning fork, but only if the patient cooperates. Therefore, these tests are only conditionally suitable for young children, for example. The tuning fork is made to vibrate on a fixed object and then – depending on the test – held alternately in front of the external auditory canal and on the bone behind the ear (Rinne test) or placed on the center of the skull (Weber test). The patient must then say when and where he hears the sound better. This allows the examiner to distinguish whether a pathological process is present and where in the ear it is likely to be localized.
Audiometry
These hearing tests are more accurate than tuning fork testing, and some can even be performed regardless of patient cooperation (objective audiometry).
- Tone audiometry: tones of varying pitch and volume are transmitted to the examinee through headphones or a sound generator placed behind the ears. As soon as he hears something, he must indicate this, for example by pressing a button. In children, the reaction to tones can be measured, for example, by reflexes or movements triggered by them.
- Speech audiometry: instead of tones, multisyllabic numbers and monosyllabic words are played. Thus, the speech comprehension can be checked.
- Objective audiometry: this method belongs to the electrophysiological examinations in which electrical activities are registered via small electrodes. In electrical response audiometry, the reactions triggered by sounds are measured directly at various locations in the brain, for example, at the cerebral cortex (electric response audiometry = ERA) or at the brainstem (brainstem evoked response audiometry = BERA). This is done with the help of the electroencephalogram. In addition, the sound waves produced by the hair cells of the inner ear can be determined at the external auditory canal using highly sensitive microphones (otoacoustic emissions = OAE).
To assess the middle ear can also measure the resistance that the eardrum and ossicular chain to the sound impinging from the outside (impedance measurement), the ability of the eardrum to transmit sound (tympanometry), and the protective mechansimus of the stapes muscle to contract in the presence of noise (stapedius reflex). Changes in these measurements may be due to calcifications or negative pressure in the middle ear, for example.
Functional tests of the vestibular organ
A whole series of tests are used to get to the bottom of dizziness attacks. They take advantage of the fact that for orientation in space and coordination, the vestibular organ in the inner ear is directly or indirectly linked to other structures such as the brain, the eyes, or pressure receptors on the skin.
- Coordination tests include the Romberg test, which requires the patient to stand with eyes closed and arms outstretched, and the Unterberger test, which additionally requires the patient to stand on the spot. However, whether the balance problems originate from the vestibular organ in the inner ear or from a central location in the brain requires further investigation.
- In nystagmus testing, special glasses are used to examine in a seated position when and how a rhythmic eye movement occurs that is also present in a healthy person (for example, when looking out of a moving vehicle). In addition, such eye tremor can also be triggered in a lying patient by cold or warm water flushed into the ear (caloric nystagmus). If the side and shape of the nystagmus deviate from the usual, this provides clues to the cause of a balance disorder.
Other examinations of the ears
Imaging techniques are mainly used when changes are suspected in the bones or brain tissue:
- Since the bones in the area of the ear are strongly overlapping, there are some special techniques especially for X-ray images of the petrous bone (image according to Schüller and Stenvers, respectively).
- Computed tomography (CT) is indicated when there is suspicion of bone fractures (for example, after an accident), malformations or a tumor.
- In the latter case, magnetic resonance imaging is also used. If one injects additional contrast agent, vessels can also be depicted.