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Ear, nose and throat
Figure 22.20 The Dix–Hallpike test position.
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A B
Figure 22.21 (A) Pure tone audiometry. (B) Bone conduction testing with masking being performed.
vestibular lesion will struggle, particularly with
the eyes closed.
The Dix–Hallpike test assesses the effect
of positional change. The patient sits on an
examination couch. First test neck movements, to
make sure they are free and painless. The head is
then turned 45° to the side of test. The patient is
laid back rapidly with his head extended over the
end of the bed (Fig. 22.20). The classic response
in BPPV involves a variable latent period when
nothing happens. Then a torsional nystagmus
beating occurs to the lower ear, with a variable
feeling of vertigo. This lasts perhaps 5–30 seconds.
With repetition, the response becomes less or
absent. The condition is caused by debris in the
posterior semicircular canal. It is frequently selflimiting, but if it persists it may be cured by the
Epley particle repositioning manoeuvre. Other
positive results are possible. Persistent immediate
positional nystagmus without vertigo implies
central pathology.
Special investigations of hearing
Pure tone audiometry
A single- frequency tone is presented at standardized
levels into each ear in turn. This is done in noisefree surroundings, usually in a soundproofed booth
(Fig. 22.21). Air conduction is tested first through
headphones. A level well above threshold, as predicted
by free field testing, is chosen and the patient responds
when he hears the sound. The intensity is then reduced
in 10-dB steps until the patient cannot hear it. It is
then increased in 5- dB steps to establish the quietest
sound that can be heard—the threshold. The better
ear is tested first at 1, 2, 4 and 8 kHz, then at 250 and
500 Hz (Fig. 22.22). In conductive loss, the difference
is called the air–bone gap. This may be correctable by
surgery to the middle ear and tympanic membrane.
Speech audiometry
A pure tone audiogram does not test discrimination
(i.e. whether speech is intelligible). A speech
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Hearing level (dB)
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An earpiece is inserted into the external meatus,
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250 500 1000
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Figure 22.22 Pure tone audiograms. (A) Normal; (B) noise- induced hearing loss; (C) presbycusis; (D) bilateral conductive hearing loss.
audiogram measures the patient’s ability to
recognize words from phonetically balanced lists
delivered at different sound levels to the test ear
from a tape recording. The percentage of words
correctly repeated by the subject is noted at each
level. With normal hearing, all words are heard
(100% optimal speech discrimination (ODS)) at a
sound intensity of 40 dB. Patients with sensorineural
deafness are often unable to achieve 100% ODS and,
in particular, patients with neural/retrocochlear loss
have poor ODS (Fig. 22.23).
back and measured by the microphone. Changing
the pressure difference between the external and
the middle ear causes the tympanic membrane to
become less compliant. This increases the sound
energy reflected back to the probe. These changes are
plotted graphically on a tympanogram (Fig. 22.24B).
The test also measures the volume of the canal: a
large volume indicates a tympanic perforation.
Impedance (the reciprocal of compliance) is
increased when the tympanic membrane is thickened
or the middle ear has fluid and is decreased when the
drum is hypermobile or atrophic. Tympanometry is
Tympanometry
an objective test. It has particular value in children
in the assessment of glue ear.
through which pass three channels. The first delivers
a continuous tone into the ear canal during the test
(probe tone); the second has a microphone to record
the sound intensity level within the ear canal; the
third channel connects to a manometer so that the
pressure within the canal can be altered (Fig. 22.24A).
The external meatus is a rigid tube with a
compliant end (the drum). Normally the middle ear
and ear canal pressures are equal, and most of the
sound introduced into the meatus is transmitted into
the ear; only a minimum of sound energy is reflected
Otoacoustic emissions
When a click or tone- burst is played into the ear,
a very small noise is emitted in return, probably
arising from the outer hair cells. These emissions
are particularly prominent in neonates, but become
increasingly difficult to elicit with age. Testing does
not require cooperation. When there is hearing loss
there is no response. The technique is valuable in the
screening of neonates and forms the backbone of the
Universal Neonatal Hearing Screen programme.
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TERIAL FREE FIELD / EARPHONE
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SPEECH LEVEL RIGHT LEFT% %
Figure 22.23 A speech audiogram.
Evoked- response audiometry
A click presented to the ear causes a nerve impulse
to be sent to the auditory cortex via the brainstem.
If a large number (>2000) of responses are averaged,
then evoked responses in brainstem and cortex can
be seen and amplitudes and latencies measured.
The auditory brainstem response is not affected
by sedation and the main indication is in the
establishment of hearing thresholds, especially in
infants. Cortical- evoked responses are less widely
used. They require an awake and alert patient.
Special tests of balance
Caloric testing is the most commonly performed
routine test of the vestibular end- organ. The patient
lies on a couch with the head up 30° in order to
bring the lateral semicircular canals into the vertical
plane. With the patient fixing on a point in central
gaze, each external ear canal is irrigated with water
at 30°C, and then at 44°C for 30–40 seconds, with
suitable intervals. Cold water induces nystagmus
away from the irrigated ear and the opposite for
COMMENTS:
warm water (COWS: cold opposite, warm same).
The modern testing technique involves using hot
and cold air rather than water, to avoid causing ear
infections or perforations. The induced nystagmus
is recorded and analysed using videonystagmography, which uses infrared video systems for a more
detailed observation, recording and analysis of these
eye movements, whilst preventing optical fixation
(Fig. 22.25) (see also Frenzel’s glasses above). Periph-
eral lesions tend to cause a diminished response on
one side (a canal paresis). A directional preponderance may be caused by central disorders, especially
in the brainstem. An alternative to caloric testing is
the video head impulse test (vHIT), an objective test
of the vestibulo- occular reflex (VOR) and indicative of peripheral vestibular dysfunction if abnormal
(Fig. 22.26).
Radiological examination
Computed tomography scanning is the investigation
of choice, but it is not a substitute for clinical
assessment of chronic ear disease. It is not specifically
diagnostic of cholesteatoma (Fig. 22.27), but is useful
476
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PROBE S/N: 13153900
TYMP SCREENING
m1
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Ytm 226 Hz
EARCANAL VOLUME: 0.9
TYMP 1:
GRADIENT:
REFLEX:
TYMP SCREENING
EARCANAL VOLUME: 1.0
TYMP 1:
GRADIENT:
REFLEX:
Figure 22.24 (A) A tympanogram being performed. (B) A tympanogram.
–400
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in cranial trauma (Fig. 22.28) and in the evaluation
of temporal bone neoplasia. Magnetic resonance
imaging (MRI) is more useful in identifying soft
tissue abnormalities in the cerebellopontine angle,
especially vestibular schwannoma (Fig. 22.29).
These tumours present with asymmetric sensorineural hearing loss. MRI also helps assess tumour
spread outside the temporal bone. CT angiography
helps in assessment of pulsatile tinnitus and vascular
lesions. Formal angiography is useful for embolization
of vascular tumours.
on each side. The lateral cartilages provide support
for the nostrils, especially in inspiration (Fig. 22.30).
The nasal cavity is divided by the nasal septum,
formed of cartilage anteriorly and bone posteriorly
(Fig. 22.31). The lateral wall of the nose is formed
by the three nasal turbinate bones: inferior, middle
and superior (Fig. 22.32). Under each turbinate is a
corresponding meatus. The nose constantly produces
mucus—a pint a day—which is constantly propelled
backwards by the cilia to the posterior choanae,
whence it is swallowed, usually unnoticed.
The paranasal sinuses are air- filled spaces in the
bones of the facial skeleton (see Figs 22.32 and
The nose and paranasal sinuses
Anatomy
The nose (Box 22.4) is formed by the two nasal bones
which articulate with the nasal process of the maxilla
22.33). They comprise the paired maxillary, frontal
and ethmoid sinuses and the unpaired but bisected
sphenoid sinus, and form the structure of the adult
face. The ethmoidal cells or labyrinth comprises a
number of small bony cells. The sinuses open into
the nose via small drainage channels (ostia). Their
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Figure 22.25 (A) A caloric test being performed. (B) A computerized caloric test result.
mucus is swept by cilia through the ostia to be
mixed with mucus secreted by the nose. The middle
meatus is the common pathway for drainage from
the maxillary, the anterior ethmoid and the frontal
sinuses. The anterior ethmoids are important because
disease in these areas will compromise maxillary and
lymphoid tissue, part of Waldeyer’s ring, which
includes the palatine tonsils. These are largest in
childhood and regress from the age of about 8 years
onwards, although rarely they may persist into adult
life. The inferior opening of the Eustachian tube is
on the lateral wall of the postnasal space.
frontal sinus drainage. Blockage of the ostia owing to
inflammation in the nose, with retention of mucus
and secondary infection, is the presumed mechanism
for sinus infection (rhinosinusitis). The upper teeth
are closely related to the floor of the maxillary sinus;
infection here may lead to sinus problems.
The olfactory neuroepithelium of the nose is
located in the roof of the nasal cavity. Neurons run
through the cribriform plate to the olfactory bulb
lying on the floor of the anterior cranial fossa. The
postnasal space contains the adenoids, which are
Symptoms of nasal disease
The important symptoms of nasal and sinus disease
are:
Nasal blockage
Rhinorrhoea: nasal discharge
Epistaxis: nasal bleeding
Sneezing and itching
Disturbances of smell
Facial pain
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Figure 22.26 A vHIT test being performed.
Figure 22.28 Computerized tomography (CT) scan of a right ear
showing a fracture across the rmiddle ear. There is disruption and
widening of the incudo- malleolar joint.
Figure 22.27 Computerized tomography (CT) scan of right ear
showing a lateral semicircular canal fistula in a patient with
cholesteatoma.
General features
Orbital and facial pain, proptosis, diplopia,
periorbital swelling and conjunctival chemosis may
develop if infection or neoplasia spread outside the
sinuses. Pathology in the postnasal space may lead to
otological symptoms secondary to Eustachian tube
involvement.
Nasal blockage
Unilateral or bilateral blockage of the nose is common. Maximum resistance to airflow occurs at the
front of the nose near the inferior turbinate. In the
nasal cycle (2–6 hours long), one side is congested
and one side decongested at any one time. The
most common cause of bilateral or alternating
nasal blockage is allergic rhinitis. A constant blockage suggests a structural abnormality (deviated
nasal septum, nasal polyposis, adenoidal hypertrophy (children)).
Rhinorrhoea
Nasal discharge may be mucoid, purulent or watery.
It may contain blood. A purulent discharge suggests
infection, either in the nose or in the sinus. In a child,
unilateral discharge may be caused by a foreign body
retained in the nose. Mucoid discharge is more
suggestive of allergic rhinitis. Watery discharge is
indicative of vasomotor rhinitis. CSF leak is a rare
but important cause; the discharge is clear, watery
and salty in taste. Epistaxis (a nose bleed) varies in
severity from a minor intermittent problem to a lifethreatening major haemorrhage that may require
cautery. It tends to occur in children and the elderly.
The arterial supply of the nose is from branches of
the sphenopalatine artery (external carotid), and
from the anterior and posterior ethmoidal arteries
(internal carotid). These vessels anastomose in the
anterior nasal septum, the site of most epistaxis.
Epistaxis is associated with hypertension, trauma
(including nose- picking), rhinitis and bleeding
disorders.
Itching and sneezing
Sneezing is a protective expulsive reflex that helps
clear the nasal airway of irritants. Paroxysmal sneezing, associated with rhinorrhoea, nasal obstruction
and palatal and conjunctival itching, occurs with
allergic rhinitis.
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Figure 22.29 Magnetic resonance imaging (MRI) scan (A) T2 weighted (B) T1 weighted demonstrating a small left-sided intracanalicular
vestibular schwannoma confined to the internal auditory meatus.
479
Box 22.4
Functions of the nose
Respiration
Filtration
Heating
Humidification
Smell
Nasal bones
Upper lateral
cartilage
Lower lateral
cartilage
Figure 22.30 The external nose.
Disturbances of smell
Loss of smell (anosmia) or impaired sense of smell is
most often caused by nasal obstruction, for example
with nasal polyposis or allergic rhinitis. It also
follows damage to nerve fibres passing through the
cribriform plate after craniofacial trauma. Rarely, viral
infection may cause permanent anosmia. Cacosmia
is an unpleasant smell, sometimes unnoticed by the
patient, caused by chronic anaerobic sepsis in the
nose.
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Figure 22.31 The nasal septum.
Frontal sinus
Adenoids
Turbinates
Eustachian
tube
Hard palate
Soft palate
Tongue
Tonsils
Figure 22.32 The lateral wall of the nose.
Facial pain
Pain in the face is very common, but pain limited
to the nose is rare. Pain centred over a sinus may
indicate infection or, rarely, a malignancy. There are
many causes of facial pain. Some, such as cluster
headache (causing transient nasal blockage and
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Ear, nose and throat
rhinorrhoea) and trigeminal neuralgia, are functional
disorders, with well- defined features (see Chapter
16). Structural disorders, such as infection or tumour
involving facial structures, may also present with
facial pain.
Investigation should usually include imaging by
CT and MRI.
Other symptoms
Always enquire about any history of allergy. Most
people are aware of hay fever, but house dust mite
allergy is also common and can be easily tested for
with skin prick testing.
Examination of the nose and face
Inspect the nose and face from the front, side and
back in a good light. Note the colour of the skin and
any asymmetry of facial contours. Observe for scars
and pigmentary changes. With age, the tip of the
nose tends to droop. Deformities of the nasal bone
Frontal
sinus
sinus
Septum
sinus
Figure 22.33 Cross- section through the sinuses (semischematic).
and cartilage, such as saddle deformity, often follow
a nasal fracture or other destructive disorders of the
bony or cartilaginous septum. Palpate the nose and
facial skeleton, especially the orbital margins, noting
tenderness and any swelling, expansion or depression
of bone. Facial swelling is unusual in maxillary
sinusitis, but occurs with dental root infections and
in carcinoma of the maxillary antrum. Inspect and
palpate the palate and alveoli from inside the mouth
using a gloved finger.
Examine the nasal vestibule and intranasal contents
by gently pushing the tip of the nose upwards with
a finger, preferably using reflected illumination from
a head mirror. The nasal vestibule is lined with skin
and contains vibrissae (thicker hairs); these become
prominent in older men. Inspect the anterior nasal
cavity with Thudicum’s nasal speculum or an
otoscope (Fig. 22.34). The nasal septum is rarely
completely straight, but should not be so bent
that it is not possible to see the anterior end of the
inferior turbinate. The majority of nasal resistance
to airflow occurs in the front of the nose. Look for
any area of granulation on the nasal septum and for
any perforation (Fig. 22.35). Perforations may be
secondary to cocaine snorting, digital trauma (nosepicking), surgical trauma, granulomatous conditions
or inhalation of industrial dusts, notably nickel and
chrome.
Nasal polyps are usually easily identifiable by their
pale colour (Fig. 22.36) and their softness and lack of
sensitivity to probing. In a child, an apparent polyp
may be seen arising from the roof of the nose; this
should not be probed because it may be the intranasal presentation of a meningocele. In children
and adults, airflow through a patent nostril causes
misting on a cold metal tongue depressor or mirror
held at the nose. In a neonate, nasal patency is best
estimated by observing any movement of a wisp of
cotton wool held in front of each nostril after blocking each in turn with the thumb. Nasal endoscopy
(Fig. 22.37), after applying a topical decongestant
Figure 22.34 Examining the nose.
Figure 22.35 A septal perforation.
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Figure 22.37 Rigid nasal endoscopy.
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Figure 22.36 A large polyp in the right nasal cavity.
such as xylometazoline with topical lidocaine anaesthesia, allows inspection of the middle meatus for
oedema, draining pus or polyps. The postnasal space
and the opening of the Eustachian tube (Fig. 22.38)
can be seen, with the fossa of Rosenmuller, the site
of origin of postnasal space carcinomas, lying directly
above and behind. In children and young adults, look
for adenoidal swelling.
Special tests
Allergy testing
If allergic symptoms are severe, there is merit in
confirming extrinsic allergy by skin- prick testing (see
Chapter 20). An important component of treating
allergy is allergen avoidance, and the certainty of
responsible allergens may encourage compliance.
The common inhalant allergens (Box 22.5), together
with any agents that have been suspected from the
history, should be tested and compared with positive
and negative controls (histamine and saline).
Unfortunately, however, a negative response does
not definitely exclude atopy. The radioallergosorbent
test (RAST), which measures specific IgE in blood,
Figure 22.38 Endoscopic view of the Eustachian tube orifice and
the postnasal space.
Box 22.5
House dust and house dust mite
Grass pollen
Tree pollen
Weed pollen
Animal dander: cat, dog, rabbit
Feathers
Moulds
may be considered for certain food allergens,
although generally this type of testing is less specific
than skin prick testing. Nasal provocation tests are
time consuming, because only one allergen can be
tested at a time.
Common inhalant allergens
Nasal patency
Objective assessment of nasal patency is difficult.
Rhinomanometry, which measures nasal airflow and
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Figure 22.39 Coronal computerized tomography (CT) scan
of the nose showing an opaque left maxillary antrum and
evidence of periapical lucency indicating dental infection
around the adjacent molar tooth.
resistance, and acoustic rhinometry, which measures
nasal volume and
cross- sectional area, remain specialized research
tools.
Mucociliary clearance
Mucociliary clearance is a test of impaired ciliary
function used, for example, in Kartagener’s syndrome
of impaired ciliary motility. A strong, sweet taste,
such as saccharin placed on the anterior end of the
inferior turbinate, should be tasted in the mouth
about 20 minutes later.
Radiological examination
Plain X- rays are unreliable in the management
of sinus disease. Previously, lateral X- rays were
commonly used in estimating the degree of
adenoidal hypertrophy in young children. More
commonly now, clinicians would use a paediatric
nasoendoscope, which is mostly well tolerated, avoids
radiation exposure and allows direct visualization
of the postnasal space even in young children.
Endoscopic nasal examination and CT scanning are
the investigations of choice for sinus disease (Fig.
22.39). CT is useful in the management of chronic
infection, trauma and neoplasia. However, there is
a radiation dosage to the eyes, and the investigation
should be used only when the diagnosis is uncertain
or to provide accurate anatomical information
before surgery. MRI is less useful in sinus disease
because of difficulties in interpretation. MRI is
highly sensitive to changes in the mucosal lining of
the sinuses. However, it tends to over diagnose and
interpretation requires caution. It does have value in
assessing the spread of sinus neoplasia.
The throat
Anatomy
The throat includes the oral cavity, the pharynx
(oropharynx, nasopharynx and hypopharynx),
the larynx and the major salivary glands. The oral
cavity extends from the lips to the anterior faucial
pillars. The oral cavity proper is bounded by the
teeth laterally, the tongue and floor of the mouth
inferiorly and the hard and soft palate superiorly.
The pharynx extends from the base of the skull
to the cricopharyngeal sphincter (Fig. 22.40). The
oropharynx is bounded above by the soft palate
and below by the upper surface of the epiglottis. Its
anterior margin is defined laterally by the anterior
faucial pillar, containing the palatoglossus muscle,
and by the posterior third of the tongue. The
posterior pharyngeal wall is its posterior boundary.
The palatine tonsils are situated laterally between
the anterior and posterior pillars of the fauces. The
base of the tongue contains the lingual tonsils. This
lymphoid tissue, together with the adenoids and the
tubal tonsil (lymphoid tissue around the Eustachian
tube opening), makes up Waldeyer’s ring, an
important line of immunological defence. The
hypopharynx consists of the posterior pharyngeal
wall, the piriform fossae and the postcricoid area.
The piriform fossae, which comprise the lateral walls
of the pharynx adjacent to the larynx, are the routes
by which food is passed into the upper oesophagus.
The larynx is a rigid structure consisting of cartilages,
the most prominent of which are the paired thyroid
cartilages, which articulate with the cricoid cartilage
below. The epiglottis is attached to the inner surface
of the thyroid cartilage and aids the separation of
air and food passages during swallowing. The larynx
consists of three compartments (Fig. 22.41): glottis,
supraglottis and subglottis. The glottis is formed
by the vocal folds. The glottis has poor lymphatic
drainage, which may help to delay the spread of
malignancy from this area. The epiglottis extends
from the false cords below to the hyoid bone above.
It has a rich lymphatic drainage, and therefore
malignancy in this area is more frequently associated
with metastatic disease. The subglottis, which is
the narrowest part of the upper respiratory tract,
extends from the glottis to the lower border of the
cricoid.
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