Clinical Cases - Ear & Nasal Cavity
An eight year-old boy presents to his physician with a chief complaint of an earache, fever and some degree of hearing loss. The patient's case history indicates a recent viral upper respiratory tract infection. During physical exam, the physician examines the patient with an otoscope and notes an inflamed tympanic membrane that is bulging and opacified. Pneumatic otoscopy confirms the presence of fluid in the middle ear. The patient is diagnosed with acute otitis media, an infection of the mucoperiosteal lining of the middle ear which has a relatively sudden onset and short duration.
Questions to consider:
- A major factor in the pathogenesis of otitis media is dysfunction of the auditory (Eustachian) tubes. What is the function of the auditory tubes?
The normal function of the auditory (old term: eustachian) tubes is to regulate pressure within the middle ear (ventilation), protect the middle ear by preventing nasopharyngeal aspiration (protection), and allow clearance of secretions from the middle ear (drainage).
- If the ventilatory function of the auditory (eustachian) tubes is compromised, air is resorbed by the middle ear and a negative pressure, anaerobic environment is created in the middle ear. The negative pressure may result in aspiration of nasopharyngeal contents, including bacteria, into the middle ear that then proliferate to cause otitis media. Which muscle opens the auditory (Eustachian) tube?
The tensor veli palatini muscle opens the auditory tube during swallowing by pulling on the cartilage of its lateral wall.
- What surgical procedures may be used to treat the fluid build-up in the middle ear?
Surgical alleviation of fluid build-up includes myringotomy. This procedure involves making a curvilinear incision in the inferior portion of the tympanic membrane below the malleus handle. The incision should be long enough to allow good drainage, the fluid may be gently suctioned. Post-operationally, cotton should be inserted into the patient's ear to absorb the drainage.
In the case of the patient with recurrent or chronic (fluid build-up lasting for more than 2 or 3 months) otitis media, the patient may have a tympanostomy tube inserted. In the long-run, the tube equalizes middle ear pressure by preventing the early closure of the initial myringotomy opening thus artificially maintaining proper middle ear ventilation.
- What are possible complications to otitis media?
Possible intratemporal complications due to otitis media include mastoiditis, an invasive infection of the mastoid air cells which is frequently accompanied by abscess formation and invasion into surrounding bone. It is generally associated with otitis media.
Possible intracranial complications to otitis media include brain abscess, extradural abscess, subdural abscess, and meningitis.
- What would an infection of the outer ear be called? What anatomical features/structures protect the ear from injury?
An infection of the outer ear is called otitis externa. Features and structures that protect the ear include: a small opening to the auditory canal, the narrow isthmus and upward orientation of the auditory canal, hair in the auditory canal, and the presence of sebaceous and apocrine glands that produce the water-repellent cerumen (ear wax).
A 5-year-old girl was taken to the primary health care physician because she was having sore throat, high temperature and runny nose. Symptoms started a couple of days ago and her mother reported that she also complained of pain in the right ear at night. The doctor examined her tonsils and found them enlarged, and checked her ears with the otoscope and saw that both eardrums were congested and looked reddish especially on the right. He recommended decongestant medication and analgesics and requested to see the girl again a week later.
Questions to consider:
- How would you explain the congestion of both eardrums?
The auditory (Eustachian) tube provides a passage for organisms to reach the middle ear from the nasal cavity. In children the tube is more horizontal and shorter than in adults, and therefore the possibility of spread is higher. One of the earliest signs of otitis media is congestion of the eardrum that may be seen easily with otoscope.
- If the ear infection was not treated properly, what important anatomical structures are likely to be affected in the middle ear?
Neglected otitis media may lead to rupture of the tympanic membrane and loss of hearing. Ossicles may be involved, and that may lead to further deterioration of hearing. Infection may spread posteriorly to the mastoid air cells causing mastoiditis, with possible spread to the posterior cranial fossa and infection of meninges.
A 12-year-old boy was admitted to the hospital complaining of a severe sore throat and bilateral earache. He had a history of frequent infections of the palatine tonsils, which had all been treated successfully with antibiotics; however, the infections had become progressively more severe and he had missed a considerable amount of school. This bout of tonsillitis was also treated with antibiotics successfully, but the boy's physician suggested that a tonsillectomy be performed to eliminate the problem once and for all. The boy was readmitted to the hospital for surgery two weeks after his most recent infection had cleared up. The surgery was proceeding well when suddenly there was a massive amount of bleeding. After a short period, the surgeon was able to locate the bleeder and ligate it, following which the wound was closed and the patient's recovery was uneventful.
Questions to consider:
- Where is the palatine tonsil located? The lingual tonsil? The pharyngeal tonsil?
The palatine tonsil is a collection of lymphatic tissue found beneath the mucous membrane between the palatoglossal and palatopharyngeal arches. The lingual and pharyngeal tonsils are also lymphatic tissue; the lingual tonsil is located on the posterior aspect of the tongue and the pharyngeal tonsil, or adenoid, is found on the upper part of the posterior pharyngeal wall.
- What blood vessels are found near the palatine tonsil and may have been responsible for the bleeding?
The palatine tonsil is supplied by five arterial branches: the ascending palatine and tonsillar branches of the facial artery, the palatine branch of the ascending pharyngeal artery, the dorsal lingual branch of the lingual artery, and the descending palatine branch of the maxillary artery. The primary source of hemorrhage, however, is usually the external palatine vein. The internal carotid artery is usually safe during tonsillectomy, but may be damaged if it is located unusually close to the lateral side of the tonsil.
- What nerves are at risk during a tonsillectomy?
The glossopharyngeal nerve accompanies the tonsillar artery on the lateral wall of the pharynx and is particularly vulnerable during a tonsillectomy. In addition, a careless surgeon may damage the lingual nerve, which passes lateral to the pharyngeal wall, just anterior to the tonsil.
- What lymphatic structures are often secondarily affected in tonsillitis?
Tonsillitis of the palatine tonsil may spread to the lingual and pharyngeal tonsils, which are associated in a grouping designated the tonsillar (Waldeyer's) ring. The tonsillar ring is assumed to have protective significance during ingestion. The tonsils drain through the superior deep cervical lymph nodes, and thus these may also be affected. The jugulodigastric (tonsillar) node, into which most tonsillar lymphatic vessels drain, is particularly vulnerable.
- How do you explain the patient's complaint about pain in both ears?
The earache was due to spread of the infection causing swelling of the torus tubarius and subsequent closing of the auditory tube. This forces the tympanic membrane to compensate for pressure changes due to altitude or temperature, which may cause severe pain or even deafness. This condition, as well as otitis media, is commonly associated with infection of the pharyngeal tonsil.
- What is a quinsy?
A quinsy is a peritonsillar abscess in the loose connective tissue outside the capsule of the tonsil. It occurs when microorganisms manage to escape from the capsule and infiltrate the infratonsillar cleft.
Moore, Clinically Oriented Anatomy p. 1158-72; 1194, 1199.
W&B p. 235-41; 280-1.