Chapter 21 The special senses
Disorders of the ear, nose and throat
The Ear
Anatomy and physiology
The ear can be divided into three parts: outer, middle and inner (Fig. 21.1).
The inner ear contains the cochlea for hearing and the vestibule and semicircular canals for balance. There is a semicircular canal arranged in each body plane and these are stimulated by rotatory movement. The facial, cochlear and vestibular nerves emerge from the inner ear and run through the internal acoustic meatus to the brainstem (see Fig. 22.7, p. 1076).
Common disorders
The discharging ear (otorrhoea)
Discharge from the ear is usually due to infection of the outer or middle ear.
Hearing loss
Deafness can be conductive or sensorineural and these can be differentiated at the bedside by the Rinne and the Weber tests (Box 21.1) or with pure-tone audiometry. Conductive hearing loss has many causes (Table 21.1) but wax is the commonest.
Conductive | Sensorineural |
---|---|
External meatus | Congenital |
WaxForeign bodyOtitis externaChronic suppurationDrum | Pendred’s syndrome (see p. 962) |
Long QT syndrome | |
Björnstad’s syndrome (pili torti) | |
End organ | |
Advancing ageOccupational acoustic traumaMénière’s diseaseDrugs (e.g. gentamicin, furosemide) | |
Perforation/trauma | |
Middle ear | |
Otosclerosis | |
Eighth nerve lesions | |
Acoustic neuroma | |
| Cranial trauma |
| Inflammatory lesions: |
| Tuberculous meningitis |
| Sarcoidosis |
| Neurosyphilis |
| Carcinomatous meningitis |
| Brainstem lesions (rare) |
| Multiple sclerosis |
| Infarction |
Normally a tuning fork, 512 Hz, will be heard as louder if held next to the ear (i.e. air conduction) than it will if placed on the mastoid bone (Rinne positive).
If the tuning fork is perceived louder when placed on the mastoid (i.e. via bone conduction), then a defect in the conducting mechanism of the external or middle ear is present (true Rinne negative).
Vertigo
The nose
Anatomy and physiology (Fig. 21.4)
The function of the nose is to facilitate smell and respiration:
Smell is a sensation conveyed by the olfactory epithelium in the roof of the nose. The olfactory epithelium is supplied by the first cranial nerve (see p. 1071).
The nose also filters, moistens and warms inspired air and in doing so assists the normal process of respiration.
Common disorders
Epistaxis
Not infrequently, small recurrent epistaxes occur and these may require a visit to the emergency clinic for an examination and simple local anaesthetic cautery with a silver nitrate stick. If the bleeding continues profusely then resuscitation in the form of intravenous access, fluid replacement or blood, and oxygen can be administered. If further intervention is necessary, consideration should be given to intranasal cautery of the bleeding vessel, or intranasal packing using a variety of commercially available nasal packs (Fig. 21.5b). In addition to direct treatment of the epistaxis, a cause and appropriate treatment of a cause should be sought (Table 21.2).
Table 21.2 Aetiology of epistaxis
Local | Idiopathic |
Trauma – foreign bodies, nose-picking and nasal fractures | |
Iatrogenic – surgery, intranasal steroids | |
Neoplasm – nasal, paranasal sinus and nasopharyngeal tumours | |
General | Anticoagulants |
Coagulation disorders | |
Hypertension | |
Osler–Weber–Rendu syndrome (familial haemorrhagic telangiectasia) |
Nasal obstruction
Rhinitis (see p. 808). If an allergen is identified, then allergen avoidance is the mainstay of treatment. Topical steroids and/or antihistamines can be tried. If severe, then oral antihistamines or referral to an allergy clinic for immunotherapy is warranted.
Septal deviation. Correction of this deviation can be undertaken surgically.
Nasal polyps. This condition occurs with inflammation and oedema of the sinus nasal mucosa. This oedematous mucosa prolapses into the nasal cavity and can cause significant nasal obstruction. In allergic rhinitis (see p. 798) the mucosa lining the nasal septum and inferior turbinates are swollen and a dark red or plum colour. Nasal polyps can be identified as glistening swellings which are not tender. Treatment with intranasal steroids helps but if polyps are large or unresponsive to medical treatment then surgery is necessary.
Foreign bodies. These are usually seen in children who present with unilateral nasal discharge. Clinical examination of the nose with a light source often reveals the foreign body, which requires removal either in clinic or in theatre with a general anaesthetic.
Sinonasal malignancy. This is extremely rare. The diagnosis must be considered if unusual unilateral symptoms are seen, including nasal obstruction, epistaxis, pain, epiphora, cheek swelling, paraesthesia of the cheek and proptosis of the orbit.
Sinusitis
Box 21.2
Types of sinusitis
Acute | Symptoms lasting 1 week to 1 month |
Recurrent acute | >4 episodes of acute sinusitis per year |
Subacute | Symptoms for 1–3 months |
Chronic | Symptoms for >3 months |
CT scan of the sinuses or an MRI scan can demonstrate bony landmarks and soft tissue planes.
Functional endoscopic sinus surgery (FESS) is used for ventilation and drainage of the sinuses.
Anosmia
A conductive deficit of smell occurs if odorant molecules do not reach the olfactory epithelium high in the nose.
A sensorineural loss of smell is incurred if the neural transmission of smell is affected.
Some conditions predispose to a mixed (conductive and sensorineural) loss of smell.
The throat
Anatomy and physiology
The nasopharynx: extending from the posterior nasal openings to the soft palate
The oropharynx: extending from the soft palate to the tip of the epiglottis
The hypopharynx: extending from the tip of the epiglottis to just below the level of the cricoid cartilage where it is continuous with the oesophagus.
You may also need

Full access? Get Clinical Tree

