11 The ear, nose, and throat

The ear is involved in both balance and hearing and is divided into the external, middle, and inner ear.

This is composed of the pinna (auricle), external auditory meatus, and the lateral wall of the tympanic membrane.

The auricle is divided into the antihelix, helix, lobe, tragus, and concha and is composed of fibrocartilage; the ear lobe is adipose only.

The tympanic membrane is a thin, grey, oval, semitransparent membrane at the medial end of the external acoustic meatus ~1cm in diameter. It detects air vibrations (sound waves). These tiny movements are then transmitted to the auditory ossicles.

This lies in the petrous part of the temporal bone and is connected to the nasopharynx via the Eustachian tube. It connects with the mastoid air cells. The tympanic cavity contains three tiny bones (ossicles: the malleus, incus, and stapes) which transmit vibrations to the cochlea and two small muscles (stapedius and tensor tympani). The chorda tympani branch of the facial nerve passes through here before it exits the skull.

This is involved in the reception of sound and the maintenance of balance. It consists of a series of interconnecting bony-walled fluid-filled chambers (vestibule, semicircular canals, and cochlea). Within the bony labyrinth is a further series of interconnecting membranous chambers (membranous labyrinth: saccule, utricle, cochlear duct, and semicircular ducts).

The vestibule and semicircular canals contain the peripheral balance organs. These have connections to the cerebellum and are important in the maintenance of posture and fixed gaze. The sensory impulses are conducted by the cochlear and vestibular divisions of cranial nerve VIII.

The main functions of the nose and nasal cavities are olfaction, respiration, and air filtration.

The upper 1/3 of the external nose is bony; the rest is cartilaginous. The inferior surface holds the anterior nares (nostrils) which are separated from each other by the bony/cartilaginous nasal septum. The lateral wall of each cavity supports a series of three ridges called turbinates (superior, middle, and inferior).

The paranasal sinuses are air-filled extensions of the nasal cavity. They are named according to the bones in which they are located: frontal, ethmoid, sphenoid, and maxilla (see Fig. 11.1). Their purpose is thought to include protection of intracranial structures and the eyes from trauma, as an aid to vocal resonance, and reduction of skull weight.

The oral cavity comprises the lips, the anterior 2/3 of the tongue, hard palate, teeth, and alveoli of the mandible and maxilla.

The tongue is involved with mastication, taste, swallowing (deglutination), and articulation. Two sets of teeth develop within a lifetime. The first set is deciduous (milk teeth). The incisors are the first to erupt at ~6 months; the rest follow within 3 years. In the permanent set, the first molar or central incisor erupts first (~6 years), the second molar erupts ~11 years of age; the third molar emerges ~18 years (wisdom teeth).

The pharynx is divided into three parts: nasopharynx, oropharynx, and hypopharynx. The nasopharynx lies posterior to the nose and superior to the soft palate. The oropharynx lies posterior to the oral cavity, extending from the soft palate to the epiglottis, and contains the tonsils. The hypopharynx lies posterior to the larynx, extending from the epiglottis to the inferior border of the cricoid cartilage, where it is continuous with the oesophagus.

The larynx lies at the level of the bodies of C3–C6 vertebrae. It connects the inferior part of the pharynx with the trachea. It functions to prevent food and saliva entering the respiratory tract and as a phonating mechanism for voice production. It is supported by a framework of hyaline cartilage connected by ligaments. The thyroid cartilage is the largest of the laryngeal cartilages and can be seen as the ‘Adam’s apple’. The nervous supply of the larynx is from cranial nerve X (sensory and motor).

The epiglottis is attached to the thyroid cartilage and occludes the laryngeal inlet during swallowing.

The main salivary glands are the parotid, submandibular, and sublingual. The sublingual glands are the smallest and their ducts open on to the floor of the mouth—as do the ducts of the submandibular glands. The parotid glands are the largest. The parotid ducts cross the masseter muscles and open into the oral cavity opposite the upper 2^nd molar teeth.

You should take a standard ‘pain’ history as in Chapter 2.

Ask about associated discharge, hearing loss, previous ear operations, or ear syringing, use of cotton buds, trauma, swimming, and air travel.

Remember that the ear has a sensory supply from cranial nerves V, IX, X, and the 2nd and 3rd cervical nerves so otalgia may be referred from several other areas (Box 11.1).

This is discharge from the external auditory meatus. Ask about other ear symptoms, when the discharge began, and any precipitating or exacerbating factors. Ask especially about the nature of the discharge:

The term ‘dizziness’ can mean different things to different people and must be distinguished from light-headedness, pre-syncope, and pure unsteadiness. Two features of the dizziness suggest that it arises from the vestibular system:

Both these symptoms can occur together, separately in time, or alone in different people. Disequilibrium (unsteadiness or veering) may accompany vestibular dizziness.

You should obtain a precise history, aiming to establish whether or not the dizziness is due to vestibular disease (Box 11.2). Ask about:

Vertigo caused by vestibular problems is most commonly rotational, but may be swaying or tilting. Whether it is movement of the person or surroundings is irrelevant.

Any rapid head movement may provoke the dizziness, but dizziness provoked by lying down, rolling over, or sitting up is specific to benign paroxysmal positional vertigo.

These are not always easy to distinguish on the history but vertigo is not so marked and gait disturbances and other neurological symptoms and signs would suggest this.

Deafness or total hearing loss is unusual. Hearing loss is usually described as being mild, moderate, or profound.

Hearing loss may be conductive, sensorineural, mixed, or non-organic.

Conductive hearing loss may be due to pathology of the ear canal, eardrum, or middle ear. Sensorineural hearing loss is caused by disease in the cochlea or the neural pathway to the brain. (See Box 11.3.)

You should take a full history as in Chapter 2. In particular, note:

Only diagnose after fully excluding an organic cause. In such cases, there may be a discrepancy between the history and clinical and audiometric findings.

As well as the full standard history, ask the patient about the character of the tinnitus, associated hearing loss, how the tinnitus bothers them (i.e. is sleep or daily living affected) and any previous history of ear disease as well as the full standard history. (See Box 11.4.)

Remember to distinguish tinnitus from complex noises (e.g. voices, music) which may constitute auditory hallucinations.

As well as the full standard history ( Chapter 2), establish:

Ask about the specific character of the discharge which is often very helpful in deciding aetiology. See Box 11.5.

The terms ‘catarrh’ and ‘postnasal drip’ should be reserved only for complaints of nasal discharge pouring backwards into the nasopharynx.

This is a nasal haemorrhage or ‘nose-bleed’. The anterior septum, known as Little’s area, is the point of convergence of the anterior ethmoidal artery, the septal branches of the sphenopalatine and superior labial arteries, and the greater palatine artery. A common site of bleeding.

Epistaxis is most commonly due to spontaneous rupture of a blood vessel in the nasal mucous membrane.

Your history should explore the possible causes (see Box 11.6).

Distinguish between anterior bleed (blood running out of the nose, usually one nostril) and posterior bleed (blood running into the throat or from both nostrils).

Sneezing is a very frequent accompaniment to viral upper respiratory tract infection and allergic rhinitis. It is commonly associated with rhinorrhoea and itching of the nose and eyes.

Ask about exacerbating factors and explore the time-line carefully, looking for precipitants.

Patients may complain of a ? sense of smell (hyposmia) or, more rarely, a total loss of smell (anosmia). Ask about the exact timing of the hyposmia and any other associated nasal symptoms.

Nasal deformity may occur as a result of a trauma causing pain ± swelling ± epistaxis ± displacement of nasal bones and septum.

Disruption of the bones and nasal septum may produce a ‘saddle’ deformity. Other causes of a ‘saddle’ nose include Wegener’s granulomatosis, congenital syphilis, and long-term snorting of cocaine.

Acne rosacea can cause an enlarged, red, and bulbous rhinophyma. Widening of the nose is an early feature of acromegaly.

Facial pain is not normally due to local nasal causes. More frequently, it is related to infection within the sinuses, trigeminal neuralgia, dental sepsis, migraine, or mid-facial tension pain.

This is the sensation of a lump in the throat (globus pharyngeus or globus syndrome). It is important to ask about symptoms of gastro-oesophageal reflux or postnasal drip.

It is occasionally associated with a malignancy. You should ask about dysphagia, odynophagia, hoarseness, and weight loss.

Neck lumps are usually secondary to infection but a minority are due to malignant disease. The most common cause of neck swelling is lymph node enlargement. A comprehensive history and examination of the head and neck is important.

In the adult, it is worth remembering that metastatic neck disease may represent spread from structures below the clavicle including lung, breast, stomach, pancreas, kidney, prostate, and uterus. If malignancy is suspected, the history and examination should include a search for symptoms and signs in other systems.

As well as the full standard history, ask especially about:

This is an alteration in the quality of the voice. There are several causes which your history should be aimed at identifying including:

This is offensive-smelling breath. It is commonly caused by poor dental hygiene or diet. Tonsillar infection, gingivitis, pharyngeal pouch, and chronic sinusitis with purulent postnasal drip can also cause bad breath.

This is a noise from the upper airway (see also Chapter 6) and is caused by narrowing of the trachea or larynx.

The main causes of stridor in adults are laryngeal cancer, laryngeal trauma, epiglottitis, and cancer of the trachea or main bronchus.

The otoscope (or auroscope) allows you to examine the external auditory canal, the eardrum, and a few middle ear structures.

The otoscope consists of a light source, a removable funnel-shaped speculum, and a viewing window which often slightly magnifies the image (Fig. 11.3).

On many otoscopes, the viewing window can be slid aside to allow insertion of instruments (e.g. scrapers and swabs) down the auditory canal.

The following is the method for examining the patient’s right ear. Examination of the left ear should be a mirror-image of this.

See cranial nerve VIII in Chapter 8.

See Box 11.7 for rhinitis.

Assess whether air moves through both nostrils effectively.

The postnasal space (nasopharynx) can be examined using fine-bore endoscopy. This is done by trained professionals; the student or non-specialist should examine the anterior portion of the nose only.

This is described under cranial nerve I in Chapter 8.

The reader should revisit the anatomy of the sinuses and Fig. 11.1. The frontal and maxillary sinuses are the only two that can be examined, albeit indirectly.

Ensure that the room is well lit. You should have an adjustable light-source. An otoscope or pen-torch should be adequate for non-specialists. (See Fig. 11.5.)

This is reserved for any abnormal or painful areas which you have detected on initial inspection.

Palpate the cervical and supraclavicular lymph nodes ( Chapter 3), thyroid ( Chapter 3), and look for any additional masses.