Clinical Examination of the Ear
Equipment for Ear Examination
Both indirect and direct light sources are used
1. Bull’s eye lamp-indirect light source.
2. Head mirror.
3. Head light-direct light source.
4. Ear specula of various sizes-The largest speculum which can be conveniently inserted into the ear canal should be used.
5. Siegel’s pneumatic speculum.
6. Tuning fork-256, 512, 1024 Hz is preferred to assess the speech frequency.
7. Jobson Horne probe can be used as a cot ton wool carrier to clean the discharge from the external auditory canal before examining the tympanic membrane.
8. Tilley’s or Hartmann’s forceps.
9. Eustachian tube catheters.
10. Otoscope-It gives a magnified view of the part to be examined.
11. Suction apparatus-This is one of the important equipment in ENT and is used to remove the secretions from the external ear and helps in proper examination.
12. Microscope-Either attached with ENT equipment unit or separate entity.
13. Otoendoscope.
In examining the ear with a forehead mirror good illumination is necessary. Any fairly powerful lamp such as Bull’s eye lamp will be sufficient.
For direct examination patient is seated sideways in such a way that examiner faces the ear to be examined with a good source of light and direct this light on to the auditory meatus. On completion of the above examination, patients head is tilted lightly opposite from the ear being examined.
The pinna is held between thumb and index finger of left hand when examining right ear and of the right hand when examining the left ear and ear is pulled upwards, backwards, outwards in adults, downwards and laterally in infants and young children. The other three fingers are placed on the temporal region serving as fulcrum. This manipulation will straighten the ear canal to a certain extent and provide a better view in preliminary examination.
In case where canal is wide and follows a straight line, this examination permits examiner to inspect the ear drum without the use of a ear speculum. The following points to be examined during this procedure.
External auditory canal-may show the following abnormalities:
• Narrow canal
(i) Congenital- atresia
(ii) Acquired – scar following trauma, bums, bony tumor like osteomas, etc.
• Wide canal: Patients in whom tympano mastoidectomy is done, syphilis, oto sclerosis.
• Foreign body: Vegetative and non-vegetative.
• Impacted wax: Hard blackish mass occluding whole of the external auditory canal.
• Tumor: Both benign and malignant.
• Discharge: Profuse and thin discharge usually from middle ear pathology, whereas slight and thick discharge from the external auditory canal.
2. Aural Speculum Examination (Instrument examination)
For this examination a proper and adequate size aural speculum preferably black coated is selected and introduced into the external auditory canal. Aural speculum will help examination of deep meatus and tympanic membrane. Most commonly used speculum is Toynbees and Gruver’s speculum.
Aim of this speculum is to straighten the canal and it should be long enough to reach the deepest obstacle which is at the junction of the bony and cartilaginous canal. Specula are circular with diameters varying between 2 and 7 mm. The speculum used should correspond to the size and permeability of the canal. In rare cases, it may be necessary to fall back upon forced dilatation of the canal to examine the drum. In such cases a dilating speculum can be used the best being Moores instrument. The dilation is extremely painful and should be performed under general anesthesia. When greater precision and details are required a special speculum like seigel’s pneumatic speculum or an endoscopic speculum or otoendoscope or otoscope can be used.
Technique of speculum examination: Patient is placed as per direct examination when the examiner focuses the light from his head mirror or head light on to the auditory meatus. The pinna is held between the middle and ring fingers of the left hand and pulls upwards and backwards. The speculum is held in the right hand and gently introduced into the canal. Once speculum has been introduced it is held in place by the thumb and index finger of the left hand in order to free the right hand for cleaning and probing. The speculum should be introduced with the utmost gentleness with a slow rotatory movement to facilitate its passage. One should not be surprised when the patient coughs while introducing the speculum which is due to irritation of auricular branch of vagus nerve.
3. Palpation of the External Auditory Canal This examination is made directly with finger or with instruments.
• Finger Palpation: Direct digital palpation is done by inserting the tip of the index finger in to the canal. By this the consistency of these is felt and also the condition of the mandible can be felt.
• Instrumental: The probe or stylet which is preferred and introduced through the speculum which will prevent instruction of examiner’s vision. It helps to determine the consistency, shape and direction of a fistula.
4. Otomicroscopic examination (EUM) is of more precise diagnostic method. When canal is obstructed by secretion or foreign body it is necessary to clean the canal as completely as possible either by dry mopping or suction cleaning under microscopic vision.
Examination of the Tympanic Membrane
To make an effective examination of tympanic membrane it is first necessary to be properly oriented with the normal anatomy of the tympanic membrane. To achieve this, the examiner should first examine the upper part of the drum and look in front of its upper pole for a small yellowish prominence. This is the short or lateral process of malleus. This landmark is particularly important since it is almost always present even when the re t of malleus has disappeared.
From this Prominence (Short or Lateral Process) Originate
1. Anteriorly. A horizontal line, often scarcely perceptible extending to the periphery of the drum. this is the anterior malleolar fold.
2. Posteriorly. A small similar line, but a little longer, this is the posterior fold, or posterior malleolar fold.
3. Inferiorily and posteriorly a whitish bony landmark is seen at an angle of 45° called handle of malleus and its tip is called the umbo. The convexity of the umbo will be directed medially towards middle ear.
. A light reflex can be observed, triangular in shape which is placed anteriorly and inferiorly called Cone of light. The cone of light is always projecting anteroinferiorly in normal tympanic membrane because the tympanic membrane is placed obliquely in the deep part of the external auditory canal.
It is customary to divide the drum topographically into four sectors or quadrants. This is done by drawing an imaginary line horizontally touching the tip of the umbo, and a second line vertically along the long axis of the handle of malleus. The quadrants are known as:
• Anterosuperior quadrant
• Posterosuperior quadrant
• Anteroinferior quadrant
• Posteroinferior quadrant.
After orientation is achieved the tympanic membrane should be examined in relation to:
I. Color.
II. Position.
III. Mobility.
IV. Changes in surface.
I. Color
Normal drum appears grayish white. If this color is changed some pathological condition should exists as follows.
• Congested drum: Indicates an inflammation, e.g. acute otitis media, myringitis bullosa, active otosclerosis, glomus jugularis, excessively crying child, etc. Congestion with yellowish tint is sometimes the sign of an acute suppurative otitis media. In stage of suppuration the congestion may be diffuse or localized. Localized in the handle of the malleus in acute otitis media or in subacute otitis media. Generalized congestion in acute simple or necrotising otitis media.
• Dark grey slate color: This color is an indi cation of tubal occlusion. This type of drum does not light up well (Dull appearance).
• A dull white, thickened, cotton-like drum, is found in certain types of sclerosis (senile) or following scarring and changes after otitis media popularly called as chalky white patch or tympanosclerotic patch.
• A dull lusterless occasionally bulging tympanic membrane is seen in secretory otitis media or glue ear.
• A slight vasodilatation of blood vessels caused by the irritation of the canal, or probing with a stylet, should not be confused with a pathological condition. Such congestion may be especially pronounced along the handle of malleus.
• A blue drum is sometimes found when infection is entirely absent. It is seen in transudative type of otitis media, glomus juglare, high jugular bulb, cholesterol granuloma and Van der Hoeve syndrome.
• A dark blue drum is seen in case of hemotympanum following head injury.
II. Position
Normally, the drum inclines downwards and medially. The upper portion is much more closer to the examining eye than it’s lower portion. The drum may change position so that it protrudes outwards towards the examiner or it may be pulled i ward towards the tympanic cavity. The following are the commonly known abnormal position:
Bulging drum: Apparent increase in length of the handle of malleus, decrease in the short process and absence of the cone of light. The bulge may be due to blood (trauma, hemorrhagic otitis media), pus (purulent otitis media), and air following tubal insufflations or tumors.
Retracted drum: Apparent shortenting of the handle of malleus, exaggeration of the prominence of the short process and anterior and posterior malleolar folds and distortion of the cone of light reflex. It may be due to insuff icient tubotympanic aeration (eustachian tube dysfunction) or adherence of the drum to the medial wall of the middle ear cavity (atelectatic drum). The retracted tympanic membrane has been classified into four grades depending on the amount of retraction of pars tensa (Sade’s classification).
Grade 1 Mild retraction not touching the long process of incus.
Grade 2 Retracted drum touching the long process of incus.
Grade 3 Retracted drum touching (he promontory.
Grade 4 Drum plastered to the promontory
Retraction of Pars flaccida has been classified into four grades according to Tos’s classification:
Grade 1: Mild attic retraction, without touching the neck of malleus
Grade 2: Attic retraction touching neck of malleus.
Grade 3: Limited outer attic wall erosion with extent beyond 0sseous malleus.
Grade 4: Severe outer attic wall erosion
III. Mobility
Mobility can be examined with the aid of seigle’s pneumatic speculum or by valsalva maneuver. During compression the triangular light reflex changes shape and the handle of malleus moves. If it does not change or move there is evidence of more or less complete loss of mobility of tympanic memebrane
The mobility is decreased or absent in:
• Adhesive otitis media which may be due to adhesion and scars following necrotizing otitis media.
• Ankylosis of the ossicular chain.
• Eustachian tube dysfunction.
Other methods of testing the mobility are by increasing the air pressure inside the middle ear cavity by insufflations of the eustachian tube while at the same time examining the drum through an otoscope which is called as Toynbee’s maneuver. The tympanic membrane also seen moving along with breathing in case of patulous eustachian tube called as hyper mobile tympanic membrane.
IV. Changes in the Surface
In pathological conditions the following changes can occur on the surface of the membrane calcareous deposits (tympanosclerotic patch), scars or thinned out membrane, bullas and perforation.
(a) Calcareous deposits: These look like white plaques of varying sizes and shapes, resembling small pieces of plaster of paris on the drum.
(b) Bulla: Bullas vary in number and are seen by the examiner as grey, reddish or bluish in color, resembling small pearls attached to the surface of the drum.
The location of a perforation is extremely variable. Determination of the exact location is most essential for diagnostic therapeutic and prognostic accuracy. The perforation may be central, attic or marginal.
MIDDLE EAR
Direct examination of the middle ear is not possible under normal conditions. Only a small area can be observed through the perforated or thin drum, i.e. a part of the incus, a shadow of the round window niche and in case the drum is extremely thin the chorda tympani nerve is seen.
In case of large central perforation labyrinthine wall, promontory and ossicle may be seen. The stapes may also be seen in posterosuperior perforations.
Changes in the tympanic membrane may give us an indication as to the condition of the middle ear cavity and its contents. All these parts may however be hidden by granulations or polyp arising from the middle ear.
Instrumental Examination
A blunt probe or stylet is used to test the softness of the granulation tissue, point of origin of the polyp, resistance of the promontory, denuded bone in an osteitic area and orifice of a fistula.
Eustachian Tube
It is a communication canal between the middle ear and the pharynx. It maintains the equilibrium between the pressure of the middle ear and the atmosphere. Any obstruction whether partly or complete causes a reabsorption of air from the middle ear with consequent retraction of the drum as a result of a higher atmospheric pressure. Due to its deep-seated anatomical location, the eustachian tube can only be examined indirectly with the help of several instruments and various methods. To test eustachian tube patency it is necessary to insufflate air into the eustachian tube by various methods such as:
• Val salva maneuver
• Toynbee maneuver
• Politzerization
• Catheterization
• Frenzel’s maneuver (nasopharyngeal pressure test).
Tuning Fork Tests
The commonly performed tests are Rinne Weber and absolute bone conduction tests. The commonly used tuning fork tests are of the frequencies of 256. 512 1024. The details of the technique have been described under the chapter of hearing evaluation.
Fistula Test
It is done by applying intermittent pressure over the tragus. or by seigelization with an pneumatic speculum. Ask the patient to look straight ahead, and check for nystagmus directed towards the opposite side. The patient may complain of vertigo. (Details are given in examination of the labyrinthine function).
Facial Nerve
It is important to differentiate between upper motor neuron palsy and lower motor neuron palsy by asking the patient to show various facial expressions like:
• Frowning (wrinkling of the forehead)
• Movement of the eyelids (closing of the eyes)
• Smiling or showing the teeth (angle of the mouth).
• Loss of nasolabial fold.
Examination of the Eye
Inspection of the eye may reveal features such as hypertelorism or coloboma associated with congenital hearing disorder syndrome. The presence of blue sclera (osteogenesis imperfecta) and interstitial keratitis (congenital syphilis, Cogan’s disease) should be noted.
On fundoscopy, papilloedema may be seen in space occupying lesions such as cerebellopontine angle tumors, temporal lobe abscess, otitic hydrocephalus. Eye movements for nystagmus should be observed. The absence of corneal reflex is usually a late sign of acoustic neuroma.
Examination of Other Cranial Nerves
Paralysis of the VI nerve may be associated with lesions in the petrous apex. e.g. (Gradenigo’s syndrome). The involvement of last four cranial nerves are frequently associated with stage 3 malignant otitis externa and advanced glomus jugulare tumor. Loss of corneal reflex is seen in acoustic neuroma.
Examination of the Nose and Throat
A full examination of the nose and throat must always be carried out to rule out rhinitis, sinusitis, pharyngitis, tonsillitis, nasopharyngitis, etc.
Functional Examination of Hearing Plethora of clinical tests of hearing were introduced in the 19th century and, although, the majority have been superseded by more sensitive and reliable audiometric tests, some knowledge of these clinical tests is of value.
Clinical tests of auditory function may be divided into four types:
1. Finger friction test: Rubbing or snapping of the forefinger and thumb is a test commonly employed by neurologists, for screening for both threshold of hearing deficits and sound localization.
2.Lever pocket watch test: With the introduction of the Quartz watch, lever pocket watch tests, have become obsolete, although for many years they were a valuable tool in audiometric screening in the absence of more sophisticated equipment.
3. Speech test: Speech test can be done in any of the following ways. However, free field speech test is most popular. These are
a) Freefield speech test by whisper.conversation
(b) Recorded voice test (c) Speech audiometry.
(d) Monitored speech through a closed circuit. In this the patient must be 20 feet from the examiner.
Requirements for Speech Test
• Testing room should be reasonably quiet.
• The eye must be shielded to prevent lip reading.
• The ear under test is directed towards the examiner.
• The non-test ear is blocked by assistant’s index finger on tragus.
• Speech test material should be spondee and phonetically balanced, example:
“Black Bird”, “night tight”, etc.
• Whisper test should be done with whisper with residual air after an ordinary expiration.
• Speech materials if audible at a distance of 20 feet are considered to be normal.
• Despite these precautions, great care must be exercised in using clinical speech tests to assess auditory thresholds.
4. Tuning fork tests: The most clinical information may be obtained using tuning forks that vibrate naturally at 256,512, 1024 and 2048 Hz. These are the frequencies commonly used in clinical practice.
The following precaution should be taken:
1. The test should be performed in a quiet room.
2. The prong should be struck sharply against some resistance, e.g. Elastic object like, hard rubber, thenar eminence, and femoral condyle.
3. The prong should be struck at a point about one-third of its length from the free end, thus keeping overtones to a minimum and producing a pure tone.
The following tuning fork tests are commonly used in practice.
• Rinne’s test
• Weber’s test
• Absolute bone conduction test (Modified Schwabach’s test).
Rinne’s Test
In this test the vibrating tuning fork is kept over the mastoid and when the patient indicates that the sound has stopped, the tuning fork is placed 2.5 cm in front of the external auditory canal . Rinne is said to be positive if the patient still hears the sound and negative if the sound is not heard. Alternatively, the vibrating tuning fork is placed in front of the external canal and on the mastoid intermittently and the patient is asked to indicate with which the hearing is better.
In cases with severe unilateral sensorineural deafness, the vibrating tuning fork may be heard when placed on the ipsilateral mastoid but not in front of the ear. This is due to trans- mission of the vibrations to the healthy ear and is referred to as a ‘false Rinne negative’ and it may be differentiated from a true negative by masking the non test ear with Barany’s noise box.
Weber’s Test
This test is performed in conjunction with the Rinne test and is of particular value in cases similar tuning forks (512) struck with moderate intensity and held at 25cms from each ear. Malingeer will say that he hears in the normal ear only. The fork on the deaf side is advanced by 3 inches towards the ear. Patient who is malingering deafness will deny hearing the sound at all.
2. Chimani Moos test: A modification of the Weber test to detect non-organic hearing loss. If a tuning fork is placed on the forehead the malingerer states that he hears the sound in his good ear (simulating a sensor neural deafness). If the meatus of the good ear is occluded, the truly deaf patient still hears the sound in the occluded ear but the malingerer may deny that he hears the tuning fork at all.
Others tests being: Teal test and Lombard test.
POINTS TO REMEMBER
1. Tragal tenderness can be elucidated in case of furunculosis of external ear .
2. The site for eliciting the mastoid tenderness is over the cymba concha, midpoint of posterior border of the mastoid and tip of the mastoid.
3. False negative Rinne is seen in severe sensor neural hearing loss.
4. Tuning fork tests are done for subjective assessment of hearing.
5. Gelle s test is an excellent method of determining the functioning of the ossicular chain and especially the stapes.
6. Toynbees maneuver is done to test the mobility of the tympanic membrane.
Hyper mobile tympanic membrane can be seen in patulous eustachian tube.
