OTHER VARIETIES OF FOREIGN BODIES, such as grains of corn, beans, peas, cherry-stones, beads, buttons, pieces of slate-pencil, are found in the external canal, and the symptoms that are present arise partly from the presence of the body, but more frequently from the irritation produced by attempts at removal.
SUBJECTIVE SYMPTOMS.—Difficulty of hearing, often due to the foreign body filling up the external canal and thus excluding all sound-vibrations. Tinnitus aurium and vertigo are often present, and caused by pressure of the body on the tympanic membrane with resulting abnormal labyrinthine pressure; also a variety of reflex conditions are noted as a result of the presence of a foreign body in the external canal, such as coughing and vomiting, partial paralysis, etc.
OBJECTIVE SYMPTOMS.—The appearance of the external canal will depend greatly upon the amount of pressure that the foreign body has exerted. For instance, a body loosely lying in the canal will irritate but little; on the contrary, a hard body like a cherry-stone firmly impacted in the canal will quickly cause a severe inflammation.
DIAGNOSIS.—As a rule, the foreign body can be readily seen with the aid of the mirror and speculum, unless the canal has become swollen to such an extent as to hide the body from sight. Probing and such-like procedures are not advisable.
TREATMENT.—The question comes up if it is good practice to make an attempt at immediate removal of a foreign body if the external canal is in a condition of acute inflammation. Unless grave head symptoms are present it is often good practice to delay, and reduce the inflammation by proper treatment, and then remove the foreign body. In other words, there is more risk by a forcible removal during a stage of acute inflammation than to permit the foreign body to remain until the inflammatory stage is past. Numbers of cases are on record where foreign bodies have remained for years in the external canal without causing serious sequelæ. Also, be sure a foreign body really exists in the canal, as it is not uncommon for patients to come with the statement that such is the case, and yet no foreign body has been discovered.
The majority of foreign bodies can be removed by the use of the syringe and warm water. The impacted bodies—and particularly those having a hard, smooth surface—present the greatest difficulties. A good plan is to try first the syringe and warm water, and if not successful try with a toothed angular forceps to grasp the body. If, as is often the case, it is found that the forceps slips off the body, then the curved blunt hook is to be used. This can be passed by the body and then turned on its axis, so that the hook is firmly placed behind it, and then a slow upward movement will often dislodge the body. On some occasions I have used two hooks, holding the body between them, and thus dragging it out. It is also better to desist after a fair trial until a succeeding day, rather than make excessive efforts at removal, which will often cause violent inflammation to follow. After the body is dislodged examine the condition of the tympanic membrane, as this is often found to be perforated by the foreign body.
Diseases of the Middle Ear.
ANATOMY.—The cavity of the middle ear is of small dimensions: antero-posterior diameter, 13 mm.; vertical diameter at the anterior part, 5.8 mm.; vertical diameter at the posterior part, 15 mm.; transverse diameter at the anterior part, 3-4.5 mm.; transverse diameter at the opposite drumhead, 2 mm. (Von Tröltsch). It is situated in the petrous portion of the temporal bone and surrounded by bony walls, with the exception of the opening covered by tympanic membrane and the opening of the Eustachian tube, having a mucous periosteal covering, very thin, transparent, and colorless. This membrane covers not only the tympanic cavity, but is reflected over the chain of small bones and tendons of the tensor tympani and stapedius muscles. It is essentially a mucous membrane, and may be considered a continuation of the naso-pharyngeal mucous membrane reflected through the Eustachian tube to the middle-ear cavity; also subject to the same pathological changes as other mucous membranes.
The tympanic cavity normally is an air-filled cavity, and allows of free vibration of the tympanic membrane and its ossicles, as well as the membrane covering the oval and round foramina; and it is readily understood that any interference with the vibration of this sound-conducting apparatus will at once affect the hearing.
Its arterial blood is supplied from the middle meningeal, stylo-mastoid, ascendant pharyngeal, posterior auricular, tympanic, and internal carotid arteries. These freely anastomose with each other. The veins pass internally through minute openings of the petrosal squamous fissure to the veins of the dura mater, and thence into the superior petrosal sinus, and also externally into the venous ring surrounding the tympanic membrane, and also to the veins of the meatus (Schwartze). This is important to bear in mind, as furnishing an easy passage for the extension of middle-ear inflammation to the brain membranes.