5. PHYSIOLOGY
• pressure equalization,
• mucociliary clearance and “drainage,”
• protection from both the influences of the
nasopharyngeal environment and loud
sounds.
11. • hydrops ex vacuo model-Politzer
• flask model-Bluestone
12.
13.
14. MUCOCILIARY CLEARANCE
AND DRAINAGE
• programmed movement of the mucous
blanket out of the eustachian tube
• epithelium of the tube are covered with cilia
• goblet cells-floor of the tube
• Aquaporins
• Surfactant
• Mucins
15. PROTECTION
• the closed orifice of the cartilaginous
eustachian tube
• Lyzozyme,lactoferrin,betadefencins and
colectin
• MALT
• Surfactant proteins - host defense
• Sound protection
27. Holmquist’s method
1. A tympanogram is recorded to determine the initial
middle-ear pressure.
2. A negative pressure is created in the nasopharynx by a
pressure device connected to the nose, and the subject is
asked to swallow to establish a negative pressure of about
200 mm H2O in the middle ear.
3. A second tympanogram is recorded to evaluate the exact
negative middle-ear pressure achieved.
4. The patient is told to swallow repeatedly
5. A third tympanogram -the final middle-
ear pressure
30. Sonotubometry
• An earphone: could generate a continuous
sound of 6, 7, or 8 kHz sound of 6, 7, or 8 kHz
Æ inserted into inserted into the nostril of the
test subject the nostril of the test subject
• „Sound source: „
• A microphone embedded in a circumaural ear
muff was placed in the ear muff was placed in
the ipsilateral external auditory canal external
auditory
31. • The microphone and insert earphone The
microphone and insert earphone Æ were
connected to a heterodyne
• A continuous tone generated by the oscillator
with filter set with filter set &the earphone
inserted into the nose „
• Test sound the external auditory canal - picked up
by a calibrated condenser microphone picked up
connected to a preamplifier connected to a
sound level recorder recorder
32. When TM is not intact
• Manometry
• Forced response test
• Clearance test
• Modified inflation and deflation test
33. My ref
• Cummings 3rd edition
• Bluestone CD, Shurin PA. Middle-ear diseases
in children: pathogenesis,diagnosis, and
management. Pediatr Clin North Am
1974;21:379–400.
• Sando I, Takahashi H, Matsune S, Aoki H.
Localization of function in the Eustachian
tube: a hypothesis. Ann Otol Rhinol Laryngol
1994;103
Notes de l'éditeur
The tensor veli
palatini, dilator tubae, and tensor tympani are innervated by
the mandibular branch of the trigeminal nerve, whereas the
levator veli palatini is innervated by the vagus nerve.
Functions of the Eustachian tube (ET)–middle ear
(ME)–mastoid (Mast) gas cell system. Pressure regulation function is
related to active dilation of the tube by contraction of the tensor veli palatini
muscle (TVP) (upper figure). Protective function is dependent, in
part, on an intact middle ear and mastoid gas cells to maintain a gas cushion
(middle figure). Clearance function is enhanced by mucociliary activity
and muscular activity during tubal closing (lower figure). EC = external
canal; NP = nasopharynx; TM = tympanic membrane.
Slow-motion videoendoscopy has revealed four steps in tubal
opening: 1) palatal elevation with medial movement of the
lateral pharyngeal wall and medial rotation of the medial lamina
(initiation of opening of the distal cartilaginous tube, presumably
by the levator veli palatini); 2) lateral movement of the
lateral wall with dilation of the orifice laterally and vertically;
3) propagation of dilation of the tubal lumen from distal to proximal
by the tensor veli palatini/dilator tubae; and 4) opening of
the proximal cartilaginous tube adjacent to the junctional
region with formation of a round to crescent-shaped lumen.58
During this event, the tube remains open for 0.3 to 0.5 seconds,
but it is open much longer during yawning.56 In normal individuals,
the eustachian tube fully opens once or twice hourly.59
Illustration depicting the probable superior portion
of the Eustachian tube lumen opening during active dilation
(DL) by the tensor veli palatini muscle (TVPM/TVP),
which is attached to the lateral lamina (LL) of the cartilage.
Sando and colleagues suggested that the superior portion (R)
is related to pressure regulation during active dilation and the
inferior portion (F) of the tubal lumen is related to protection
with its folds, glands (G), and goblet cells (GL).8 Elastin in the
hinge portion (ie, junction between the medial and lateral
laminae) aids in returning the medial lamina to the resting
position.
Illustration of the sequence of events during Eustachian tube
(ET) dilation (active opening) owing to contraction of the tensor veli
palatini muscle (TVP) during swallowing activity. A, The Eustachian
tube at rest is closed. B, The proximal end of the cartilaginous lumen
dilates first and is then followed by (C) dilation of the distal end and is
open to the middle ear (ME). D, The Eustachian tube passively closes from
the distal end to the proximal end to its resting, closed position.
To be fully opened, the dilatory muscles must overcome the
intraluminal surface tension generated by the apposition of the
mucosal surfaces. Surfactant protein B, has been identified in the secretory
granules of surface cells that line the eustachian tube
Tubal
surface tension is also influenced by the amount and composition
of tubal secretion. This is under control of the autonomic
nervous system, and increased parasympathetic tone has been
shown to impair tubal opening.
According to the classic theory of eustachian tube dysfunction
suggested by Politzer67 in the nineteenth century, the gas
contained in the middle ear/mastoid system is absorbed into
the bloodstream by the capillaries of the middle ear/mastoid
mucosa when the tube is hermetically sealed. This was termed
the hydrops ex vacuo model.
Bluestone and colleagues72 described a flask
model, in which the volume supplied by the mastoid air cell
system acts as a buffer to protect against abrupt pressure
changes and reflux of nasopharyngeal secretions into the
middle ear.
Protective function of the Eustachian tube–middle
ear–mastoid gas cell system can be visualized using the flask model. When
liquid is instilled into the mouth of the flask (nasopharyngeal end of
tube), the liquid stops in the narrow neck (isthmus of the cartilaginous
portion of the tube) owing to the presence of positive (back) pressure built
up in the bulbous portion and distal end of the narrow neck of the flask
(middle-ear gas cushion). ET = Eustachian tube; Mast = mastoid gas
cells; ME = middle ear.
FIGURE
Mucus of the tube is composed of a thick, more superficial
gel phase and a thin sol phase. The cilia move in the sol phase,
and their tips contact in the overlying gel phase, which propels
the mucous blanket.
and a group of integral membrane
proteins called aquaporins that facilitate the passage of water through cell membranes.
Surfactant potentiates the movement of
the gel over the sol phase.61,78,79 Mucins are high-molecularweight
glycoproteins and constitute the major component of
the mucous secretions.
They lubricate the epithelial surface and trap bacteria and viruses
lysozyme,
a muramidase that creates cell wall disruption; lactoferrin,
an iron-binding glycoprotein that acts synergistically with
immunoglobulins; β-defensins, antimicrobial peptides that
increase permeability of cell walls; and colectins, oligomeric
polypeptide chains that bind microbial carbohydrates and assist
phagocytosis. Additionally, cellular proliferation in the lymphatic
tissue associated with the eustachian tube (MALT) plays
an important role in the local immune response.
The primary role of SP-A seems to
be mucosal defense through facilitation of phagocytosis, and
the principal role of surfactants in antimicrobial defense may
be as releasing agents and antiadhesives
It has been
shown experimentally that these sounds lead to a coordinated
contraction of the stapedius, tensor tympani, tensor veli palatini,
and dilator tubae muscles. This muscle contraction causes
the middle ear cleft, mastoid, and nasopharynx to form one
continuous cavity to assist in the dissipation of sound pressure
a history of recent
weight loss could indicate a patulous Eustachian tube
(signs and symptoms of Eustachian tube
dysfunction, such as fluctuating hearing loss, otalgia, vertigo,
and tinnitus, including popping and snapping sounds in the ear
or autophony). Otologic symptoms during pregnancy, puberty,
flying in airplanes, swimming, and diving (especially scuba diving)
can be helpful.
When the middle-
ear pressure is ambient, the normal tympanic membrane
moves inward with slight positive pressure in the ear canal and
outward with slight negative pressure. The motion observed is
proportionate to the applied pressure and is best visualized in
the posterosuperior quadrant of the tympanic membrane. If a
two-layered membrane or an atrophic scar (owing to
The tubal lumen is opened by a forced expiration
with the nasal alae held between the thumb and forefinger
with the mouth closed, which insufflates positive pressure into the
middle ear through the Eustachian tube. Confirmation of tubal
patency is by otoscopy (bulging tympanic membrane), by using a
Toynbee tube (a rubber tube with one olive tip in the patient’s test
ear and the other olive tip in the examiner’s ear; a pop can be
heard in the test ear if the test is successful), or more modern and
accurate with tympanometry. (Self-Valsalva is also a method to
inflate the middle ear through the Eustachian tube when there is
induced middle-ear negative pressure, such as during descent in
an airplane or during scuba diving.)
A nasal olive tip attached to a “Poltizer
bag” (rubber tubing attached to a rubber bulb) is inserted into
one naris while both nasal alae are compressed by finger pressure.
The patient is asked to repeat the letter K or is asked to
swallow, both of which close the velopharyngeal port, while the
examiner compresses the rubber bulb. When normal tubal
patency is present, positive pressure is insufflated into the middle
ear through the Eustachian tube. Confirmation is by the
same methods described in Figure 8–5.
The Toynbee test of Eustachian tube function.
Closed-nose swallowing results first in positive pressure
in the nose and nasopharynx, followed by a negative
pressure phase. When positive pressure is in the
nasopharynx, air may enter the middle ear, creating positive
pressure. During or after the negative pressure
phase, negative pressure may develop in the middle ear,
positive pressure may still be in the middle ear (no change
in middle-ear pressure during negative phase), positive
pressure may be followed by negative middle-ear pressure,
or ambient pressure will be present if equilibration
takes place before the tube closes. If the tube does not open
during the positive or negative phase, no change in middle-
ear pressure will occur.
Block diagram of an immittance instrument in
which a tympanogram can be obtained when the tympanic
membrane is intact. The pump-manometer system can be
employed to perform tests of Eustachian tube pressure regulation
function when the tympanic membrane is not intact.
one test represents the middleear
pressure only at one moment.
Serial determinations are more indicative of
the dynamics of tubal function in a single patient
First, a tympanogram
is obtained to determine the resting middle-ear pressure. Then
the subject is asked to perform a Toynbee maneuver, which normally
leads to negative pressure in the middle ear. The establishment
of this negative middle-ear pressure is verified by a
second tympanogram. If the second tympanogram fails to
record a change in middle-ear pressure, the subject is classified
as Toynbee negative, indicating possible tubal dysfunction. If the
maneuver is successful in inducing negative middle-ear pressure,
then the subject is asked to swallow in an attempt to equilibrate
the negative pressure. A third tympanogram is recorded
to determine whether the equilibration was successful and, if so,
to what degree. If the equilibration was not complete, the subject
is asked to swallow repeatedly. A tympanogram is recorded
between each swallow to monitor the progressive equilibration.
The pressure remaining in the middle ear after several swallows
is termed residual negative pressure. A similar approach is us
measures the ability of the Eustachian tube to
equilibrate induced negative middle-ear
One tympanogram is obtained while the patient is
breathing normally, and a second is obtained while the patient is
holding his or her breath. Fluctuation of the tympanometric
trace that coincides with breathing confirms the diagnosis of a
patulous tube. Fluctuation can be exaggerated by asking the
patient to occlude one nostril with the mouth closed during
forced inspiration and expiration or by performing the Toynbee
maneuver
1. The tympanogram records resting middle-ear pressure.
2. Ear canal pressure is increased to +200 mm H2O with
medial deflection of the tympanic membrane and a corresponding
increase in middle-ear pressure. The subject
swallows to equilibrate middle-ear overpressure.
3.While the subject refrains from swallowing, ear canal pressure
is returned to normal, thus establishing a slight negative
middle-ear pressure (as the tympanic membrane
moves outward). The tympanogram documents the established
middle-ear underpressure.
4. The subject swallows in an attempt to equilibrate negative
middle-ear pressure. If equilibration is successful, airflow
is from the nasopharynx to the middle ear.
5. The tympanogram records the extent of equilibration.
6. Ear canal pressure is decreased to 200 mm H2O, causing
a lateral deflection of the tympanic membrane and a corresponding
decrease in middle-ear pressure. The subject
swallows to equilibrate negative middle-ear pressure; airflow
is from the nasopharynx to the middle ear.
7. The subject refrains from swallowing while external ear
canal pressure is returned to normal, thus establishing a
slight positive pressure in the middle ear as the tympanic
membrane moves medially. The tympanogram records the
overpressure established.
8. The subject swallows to reduce overpressure. If equilibration
is successful, airflow is from the middle ear to the
nasopharynx.
9. The final tympanogram documents the extent of equilibration.
Sound source: was fixed tightly within the Sound source: was fixed tightly within the nostril to minimize sound leakage nostril to minimize sound leakage
connected to a heterodyne analyser analyser (consisted (consisted of an analyser analyser and a frequency oscillator) and a frequency oscillator)
The test subject sat in a quiet room with his or her mouth closed and without moving the head
He/she was asked to swallow water while the sound signal in the external ear was being recorded continuously recorded continuously
Opening of the tube was reflected -sudden increase in signal in the external ear canal (5 dB)
The active
response is due to the contractions of the tensor veli palatini
muscle, which displaces the lateral walls from the cartilage-supported
medial wall of the tube. Thus, the clinician can determine
whether tubal dysfunction is due to the material properties
of the tube or to a defective active opening mechanism.
During this test, the middle ear is inflated at a constant flow rate,
forcing the Eustachian tube open. After the forced opening of
the tube, the pump continues to deliver a constant airflow,
maintaining a steady stream of air through the tube. Then the
subject is instructed to swallow for assessment of the active
dilatation of the tube.
The method is unique in that it eliminates the “mucous
forces” in the Eustachian tube lumen that may interfere with the
results of the inflation-deflation test when an attempt is made to
assess the active opening mechanisms and the compliance of the
tube. In this test, the passive resistance is assessed, and the active
resistance is determined during swallowing. Patients with