THE EAR[5]
Surgical Anatomy--CARDINAL SYMPTOMS OF EAR DISEASE: _Impairment of hearing_; _Tinnitus aurium_; _Earache_; _Giddiness_; _Discharge_--Hearing tests--Inspection of ear--Inflation of middle ear. AFFECTIONS OF EXTERNAL EAR: _Deformities_; _Haematoma auris_; _Epithelioma and Rodent cancer_; _Impaction of wax_; _Eczema_; _Boils_; _Foreign bodies_. AFFECTIONS OF TYMPANIC MEMBRANE AND MIDDLE EAR: _Rupture of membrane_; _Acute inflammation of middle ear_; _Chronic suppuration_; _Suppuration in the mastoid antrum and cells_.
[5] We desire here to acknowledge our indebtedness to Dr. Logan Turner for again revising this chapter.
#Surgical Anatomy.#--The anatomical subdivision of the ear into three parts--the external, middle, and internal ear--forms a satisfactory basis for the study of ear lesions. The outer ear consists of the auricle and external auditory meatus, the latter being made up of an outer cartilaginous portion half an inch in length, and a deeper osseous portion three-quarters of an inch long. The ca.n.a.l forms a curved tube, which can be straightened to a considerable extent for purposes of examination by pulling the auricle upwards and backwards.
It is closed internally by the tympanic membrane, which separates it from the tympanic cavity or middle ear. The middle ear includes the tympanum proper, which is crossed by the chain of ossicles--malleus, incus, and stapes--the Eustachian tube, which communicates with the naso-pharynx, and the tympanic antrum and mastoid cells. As these cavities lie in close relation to the middle and posterior cranial fossae, infective conditions in the tympanum and mastoid cells are liable to spread to the interior of the skull. The internal ear or labyrinth lies in the petrous part of the temporal bone, its outer boundary being the inner wall of the middle ear.
Physiologically the different parts of the auditory mechanism may be divided into (1) the _sound-conducting apparatus_, which includes the outer and middle ears; and (2) the _sound-perceiving apparatus_--the internal ear and central nerve tracts. Impairment of hearing may be due to causes existing in one or other or both of these subdivisions.
The condition of the sound-conducting apparatus can be investigated by direct inspection through the speculum, and by inflation of the Eustachian tube and tympanum, while that of the sound-perceiving apparatus is ascertained partly by testing the hearing, and partly by excluding affections of the outer and middle ear. When the sound-conducting apparatus is at fault, the resulting deafness is spoken of as "obstructive"; when the sound-perceiving apparatus is affected, the term "nerve deafness" is used. The semicircular ca.n.a.ls, which are peripheral organs concerned in the maintenance of equilibration, form part of the inner ear apparatus.
CARDINAL SYMPTOMS OF EAR DISEASE.--The most important symptom of ear disease is _impairment of hearing_, which varies in degree, and may be due to lesions either in the sound-conducting or in the sound-perceiving apparatus. The sudden onset of deafness may be due to impaction of wax in the external meatus or to haemorrhage or effusion into the labyrinth. A gradual onset is more common. In children there is a great tendency for acute inflammatory conditions of the middle ear to arise in connection with the exanthemata and in a.s.sociation with adenoids. In adult life chronic catarrhal processes are more common causes of gradually increasing deafness, while in advanced age there is a tendency to acoustic nerve impairment. Certain anomalous conditions of hearing are occasionally met with, such as the "paracusis of Willis"--a condition in which the patient hears better in a noise; "diplacusis," or double hearing; and "hyperaesthesia acustica," or painful impressions of sound.
_Tinnitus aurium_, or subjective noises in the ear, may const.i.tute a very annoying and persistent symptom. These sounds vary in their character, and may be described by the patient as ringing, hissing, or singing, or may be compared to the sound of running water or of a train. They are usually compared to some sound which, from his occupation or otherwise, the patient is accustomed to hear. They may be purely aural in origin, being due, for example, to increased pressure on the acoustic nerve endings from causes in the labyrinth itself or in the middle or external ear; or they may be due to certain reflex causes, such as naso-pharyngeal catarrh or gastric irritation.
Vascular changes such as occur in anaemia, Bright"s disease, and heart disease may also be concerned in their production.
_Pain_, or _earache_, varies in degree from a mere sense of discomfort to acute agony. The pain a.s.sociated with a boil in the external meatus is usually aggravated by movements of the jaw, by pulling the auricle, and by pressure upon the tragus. The pain of acute middle-ear inflammation is deep-seated, intermittent in character, and worse at night, and is aggravated by blowing the nose, coughing, and sneezing--acts which increase middle-ear tension by forcing air along the Eustachian tube. Mastoid pain and tenderness are indicative of inflammation in the antrum or cells, and when these symptoms supervene in the course of a chronic middle-ear suppuration, they should always be regarded as of grave import. Severe neuralgia of the ear may simulate the pain of acute mastoiditis, and it must not be forgotten that earache may be traced to a diseased tooth. A careful examination, not only of the ear, but also of the throat and teeth, should therefore be made in all cases of earache.
_Vertigo_, or _giddiness_, may be produced by causes which alter the tension of the labyrinthine fluid, such, for example, as the pressure of wax upon the tympanic membrane, or exudation into the middle ear or into the labyrinth. Giddiness occurring in the course of chronic middle-ear suppuration may be significant of labyrinthine or of intra-cranial mischief, but is not necessarily so. Giddiness preceded by nausea suggests a gastric origin; if followed by nausea it points to an aural origin. In cases of suspected aural vertigo, the patient"s "static sense" should be carefully tested. He should be asked (1) to stand with both feet together with the eyes closed, (2) to stand on one or other foot with eyes closed, (3) to walk in a straight line, (4) to hop backwards and forwards off both feet. His incapacity for performing such movements should be noted. As nystagmus may be a.s.sociated with disturbance of equilibrium due to ear disease, the movements of the eyeb.a.l.l.s must be carefully tested.
Labyrinthine _nystagmus_ is of a rhythmic character, and consists of a slow and a rapid movement. Physiological nystagmus can be induced by stimulating the movement of the endolymph in the semicircular ca.n.a.ls, by syringing the ear with hot and cold water (caloric test), by rotating the individual (rotation test), and by the galvanic current.
Any departure from the normal reactions which these tests may produce, should raise the suspicion of a pathological condition of the semicircular ca.n.a.ls.
_Discharge from the ear_, or _otorrha_, is occasionally due to an eczematous condition of the skin lining the external meatus. It is then usually of a thin, watery character, and contains epithelial flakes and debris. An aural discharge is, however, most commonly of middle-ear origin. It may be muco-purulent and stringy, or purulent and of thicker consistence. A peculiar, offensive odour is characteristic of chronic middle-ear suppuration. The surgeon should smell the speculum in suspicious cases. He should never accept the patient"s statement as regards the absence of discharge, but should satisfy himself by inspection and by the introduction of a cotton-wool wick.
#The Hearing Tests.#--In testing the hearing, a definite routine method should be adopted, the watch, whisper, voice, and tuning-fork tests being systematically employed. Although the patient only complains of one ear, both must be examined. Each ear should be tested separately, and the patient should be so placed that he cannot see the lips of the examiner. While one ear is being tested, the other should be closed with the finger, and each test should be commenced outside the probable normal range of hearing. All the results should be written down at once, and the date of the test recorded, as this is essential for following the progress of the case.
_Tuning-fork Tests._--To differentiate between deafness due to a lesion in the sound-conducting apparatus and that due to labyrinthine causes, it is necessary to enter into a little more detail. The tone produced by a vibrating tuning-fork is conducted to the nerve terminations in the labyrinth both through the air column in the external meatus (air-conduction), and through the cranial bones (bone-conduction). When, in a deaf ear, the vibrations of a tuning-fork placed in contact with the mastoid process are heard better than when the fork is held opposite the meatus, the lesion is in the sound-conducting apparatus. When, on the other hand, the vibrations are heard better by air-conduction, the lesion is in the sound-perceiving apparatus. In addition to these facts, we find also that in obstructive deafness low tones tend to be lost first, while in nerve deafness the higher notes are the first to go. This may be investigated by tuning-forks of different pitch or with the aid of a Galton"s whistle. Again, in middle-ear deafness, hearing may be better in a noisy place, and be improved by inflation of the tympanum; while in labyrinthine deafness, hearing may be better in a quiet room, and be rendered worse by inflation.
#Inspection of the Ear.#--This should be carried out by the aid of reflected light, the ear to be examined being turned away from the window, lamp, or other source of light that may be employed. A small ear reflector, either held in the hand or attached to a forehead band, and a set of aural specula are required. Before introducing the speculum, the outer ear and adjacent parts should be examined, and the presence of redness, swelling, sinuses or cicatrices over the mastoid, displacement of the auricle, or any inflammatory condition of the outer ear observed. To inspect the tympanic membrane, a medium-sized speculum held between the thumb and index finger is insinuated into the cartilaginous meatus, the auricle being at the same time pulled upwards and backwards by the middle and ring fingers, so as to straighten the ca.n.a.l. The tympanic membrane is then sought for and its appearance noted.
The _normal membrane_ is concave as a whole on its meatal aspect; it occupies a doubly oblique plane, being so placed that its superior and posterior parts are nearer the eye of the examiner than the anterior and inferior parts. While varying to some extent in colour, polish, and transparency, it presents a bluish-grey appearance. The handle of the malleus traverses the membrane as a whitish-yellow ridge, which appears to pa.s.s from its upper and anterior parts downwards and backwards to a point a little below the centre. At the lower end of the handle of the malleus a bright triangular cone of light pa.s.ses downwards and forwards to the periphery of the membrane. At the upper end of the handle is a white k.n.o.b-like projection, the short process of the malleus. Pa.s.sing forwards and backwards from this are the anterior and posterior folds. The portion of the membrane situated above the short process is known as the membrana flaccida or Shrapnell"s membrane. Behind the malleus the long process of the incus may be visible through the membrane. The mobility of the membrana tympani should be tested by inflating the tympanum or by means of Siegle"s pneumatic speculum.
Various departures from the normal may be observed. _Atrophy_ of the membrane is characterised by extreme transparency of the whole disc.
Circ.u.mscribed atrophic patches appear as dark transparent areas, which show considerable mobility and bulge prominently on inflation. A _cicatrix_ in the membrane is evidence of a healed perforation, and is also transparent, but differs from an atrophic patch in being more sharply defined from the surrounding membrane. A _thickened membrane_ presents an opaque white appearance. _Calcareous_ or _chalky patches_ are markedly white, and when probed are hard to the touch; they are often evidence of past suppuration. An _indrawn_ or retracted membrane, resulting from Eustachian obstruction, is characterised by increased concavity, undue prominence of the lateral short process of the malleus and of the anterior and posterior folds, and by the handle of the malleus a.s.suming a more horizontal position. An _inflamed_ membrane, showing congestion of the vessels about the malleus or a general diffuse redness, is evidence of middle-ear inflammation. A yellow appearance of the lower part of the membrane, limited above by a dark line stretching across the drum-head, is indicative of sero-purulent exudation into the tympanum. The membrane may be bulged outwards into the meatus by the fluid, and thus lie nearer the observer"s eye than normally. A _perforation_ is usually single, and varies in size from a small pinhead to complete destruction of the membrane. The labyrinthine (inner) wall of the tympanum may be visible through the perforation, and is recognised by being on a deeper plane than the membrane, and by its hard bony consistence when touched with the probe. The diagnosis of a perforation a.s.sociated with middle-ear discharge may be further a.s.sisted by inspection during inflation, when bubbles of air and secretion are visible. When the perforation is invisible, its existence may be inferred if a small pulsating spot of light can be recognised through the speculum. _Granulations_ in the tympanum appear as red fleshy ma.s.ses of different sizes. When large they const.i.tute _aural polypi_, which are recognised by their proximity to the outer end of the meatus, their soft consistence and mobility, and the fact that the probe may be pa.s.sed round them.
Granulations and polypi usually indicate the presence of middle-ear suppuration.
#Inflation of the Middle Ear.#--Before proceeding to inflate the middle ear, the examiner should inspect the nose, naso-pharynx, and pharynx. This should be made a routine part of the examination in all cases of ear disease. As inflation is not only an aid in diagnosis, but is also of great a.s.sistance in prognosis, it is necessary that the hearing should be tested and noted before the ear is inflated. There are three methods of inflating the tympanum: Valsalva"s method, Politzer"s method, and by means of the Eustachian catheter.
In _Valsalva"s inflation_ the patient himself forces air into his Eustachian tubes, by holding his nose, closing his mouth, and forcibly expiring. This method of inflation has only a limited application and is of little therapeutic value.
_Politzer"s Method._--For this a Politzer"s air-bag and an auscultating tube, one end of which is inserted into the patient"s ear and the other into the ear of the examiner, are required. The nasal end of the bag should be protected with a piece of rubber tubing or be provided with a nozzle. The patient retains a small quant.i.ty of water in his mouth until directed to swallow. The nozzle of the bag is inserted into one nostril, and the other is occluded by the fingers of the surgeon. The signal to swallow is then given, and, simultaneously with the movement of the larynx during this act, the bag is sharply and forcibly compressed. Holt"s modification of this method consists in directing the patient to puff out his cheeks while the lips are kept firmly closed.
_Inflation through the Eustachian Catheter._--For this method, in addition to the Politzer"s bag and the auscultating tube, a silver or vulcanite Eustachian catheter is required. The silver instrument has the advantage that it can be sterilised by boiling. The patient is seated facing the light, while the surgeon stands in front of him, and, having placed the auscultating tube in position, with his left thumb he tilts up the tip of the patient"s nose. The beak of the catheter is now inserted into the inferior meatus, point downwards, and carried horizontally backwards along the floor of the nose until the convexity of the curve touches the posterior wall of the naso-pharynx. When the posterior pharyngeal wall is felt, the point of the instrument is rotated inwards through a quarter of a circle; the position of the point is indicated by the metal ring upon the outer end of the catheter. The finger and thumb of the left hand should now grasp the stem of the catheter just beyond the tip of the nose so as to steady it. It is now gently withdrawn until the concavity of the beak is brought against the posterior edge of the septum nasi. With the right hand the point of the instrument is then rotated downwards and outwards through a little more than half a circle, so that the point slips into the Eustachian orifice and the metal ring looks outwards and upwards towards the external canthus of the eye of the same side. While the instrument is maintained in this position by the left hand, the nozzle of the Politzer"s bag is inserted into the funnel-shaped outer extremity of the catheter, and inflation is gently carried out with the least possible jerking. Before withdrawing the catheter its point must be disengaged from the Eustachian opening by turning it slightly downwards. Difficulties in introducing the catheter may arise from the presence of spines and ridges upon, and deviations of, the septum, and it may be necessary to pa.s.s the instrument under the guidance of the mirror and speculum.
More accurate information is gained from the use of the catheter than from Politzer"s inflation, and it is the safer method to employ when a cicatrix or atrophied patch exists in the tympanic membrane, as by the latter method rupture of these areas might occur. Further, the catheter has the advantage of only inflating one ear, and thus preventing any undue strain being put upon the other. In children the catheter can seldom be employed, on account of the difficulty in pa.s.sing it.
Considerable information may be derived from inflation. If the Eustachian tube is patent, a full clear sound is heard close to the examiner"s ear through the auscultating tube. If the Eustachian tube is obstructed, the sound is fainter and more distant. If there is fluid in the tympanum, a fine moist sound may be detected, which must not be confounded with the coa.r.s.er and more distant gurgling sound a.s.sociated with moisture at the pharyngeal opening of the tube. If a small dry perforation exists in the tympanic membrane, the air may be heard whistling through it, while if the perforation is large, a sensation which is almost painful may be produced in the examiner"s ear. If there is fluid a.s.sociated with the perforation, these sounds may be accompanied by a bubbling noise. The effect of inflation upon the hearing must be carefully tested and recorded.
AFFECTIONS OF THE EXTERNAL EAR
#Deformities.#--The auricle, together with the external auditory meatus, may be _congenitally absent_ on one or on both sides. The condition is not amenable to surgical treatment. _Double auricles_ are occasionally met with; more frequently rudimentary _auricular appendages_ about the size of a pea, consisting of skin, subcutaneous connective tissue and nodules of cartilage occur in front of the tragus, on the lobule or in the neck. These appendages should be snipped off with scissors. These congenital deformities are due to errors in development of the mandibular arch, and are frequently a.s.sociated with macrostoma, facial clefts, and other malformations of the face.
_Outstanding ears_ may be treated by excising a triangular or elliptical portion of skin and cartilage from the posterior surface of the pinna and uniting the cut edges with sutures. Abnormally _large ears_ may be diminished in size by the removal of a V-shaped portion from the upper part of the auricle.
The term #haematoma auris# is applied to a sub-perichondrial effusion of blood, which may occur either as the result of injury to the auricle, for example in football players, or as a result of trophic changes in the cartilage and perichondrium. The latter form is not uncommon among the insane. A more or less tense fluctuating swelling forms on the anterior surface of the auricle, presenting in some cases a distinctly bluish coloration. Inflammation may ensue, and in some cases suppuration and even necrosis of cartilage may follow.
The _treatment_ in a recent case consists in applying cold or elastic compression with cotton-wool and a bandage, or in withdrawing the effused blood by means of a hollow needle. In the event of suppuration supervening, incision and drainage must be carried out.
#Epithelioma# may attack the auricle and extend along the external auditory meatus. It begins as a small abrasion which refuses to heal, and is attended with a constant ftid discharge and intense pain. The disease may spread to the middle ear and invade the temporal bone, and facial paralysis then ensues. The adjacent lymph glands are early infected. The treatment consists in removing the growth freely, and excising the a.s.sociated lymph glands at an early stage of the disease.
In inoperable cases radium or the X-rays may be employed.
#Rodent cancer# also may attack the outer ear.
#Impaction of Wax or Cerumen.#--Hyper-secretion may result from unknown causes, or it may accompany or be induced by the discharge from a chronic middle-ear suppuration. The a.s.sociation of these two conditions should be borne in mind. An acc.u.mulation of wax may be caused by the too zealous attempts of the patient to keep the ear clean, the wax being forced into the narrow deeper part of the meatus.
The chief _symptom_ of impacted wax is deafness, which is often of sudden onset. Impaction of wax causes deafness only when the lumen of the auditory ca.n.a.l becomes completely occluded by the plug. Tinnitus aurium and vertigo are sometimes present, and may be troublesome if the wax rests upon the tympanic membrane. Pain is occasionally complained of, and is usually due to the pressure of the plug upon an inflamed area of skin. Certain reflex symptoms, such as coughing and sneezing, have been met with.
It is only by an objective examination of the ear that the diagnosis can be made. The plug varies in colour and consistence, and may be yellow, brown, or black in appearance. Sometimes from the admixture of a quant.i.ty of epithelium it is almost white in colour.
_Treatment._--The ear should be syringed with a warm antiseptic or sterilised solution. The lotion is at a suitable temperature if the finger can be comfortably held in it. The ear should be turned to the light, a towel placed over the patient"s dress, and a kidney basin held under the auricle and close to the cheek. A syringe provided with metal rings for the fingers and armed with a fine ear nozzle should be held with the point inserted just within the aperture of the external meatus and in contact with the roof of the ca.n.a.l. Care must be taken that all the air is first removed from the syringe. To straighten the ca.n.a.l, the pinna should be pulled upwards and backwards by the left hand. It may be necessary to exert some considerable degree of force before the plug becomes dislodged, but this must be done with caution.
The ear should then be dried out with cotton-wool, and a small plug of wool inserted for a few hours. If pain is complained of, or if the wax is hard and cannot be readily removed, the syringing should be stopped, and means taken to soften it by the instillation of a few drops of a solution of bicarbonate of soda (10 grains to the ounce of water or glycerine), or of peroxide of hydrogen, several times daily.
#Eczema of the external meatus# is often a.s.sociated with eczema of the auricle and of the surrounding parts. Not infrequently there also exists a chronic middle-ear suppuration, which may be the cause of the eczema. Intense itchiness is the most characteristic symptom, and a watery discharge may also be complained of. Deafness and tinnitus are dependent upon the acc.u.mulation of epithelium and debris. After the ear is syringed the skin may present a dry, scaly appearance, while sometimes fissures and an indurated condition of the outer end of the meatus may be noted. Rarely is the outer surface of the tympanic membrane itself involved.
_Treatment_ consists in keeping the ear clean by syringing and careful drying. Probably the best local application is nitrate of silver (10 grains to the ounce of spiritus aetheris nitrosi). This is applied by means of a grooved probe dressed with a small piece of cotton-wool.
Care should be taken that none of the fluid is allowed to escape upon the cheek, otherwise staining of the skin occurs. A plug of cotton-wool is inserted, and the solution is re-applied at the end of a week. Sometimes the condition is very intractable.
Occasionally the vegetable parasite _aspergillus_ is present in the external meatus, and produces a condition that is liable to be mistaken for eczema. Strong antiseptic lotions are required to kill the fungus.
#Furunculosis# or #Boils#.--Boils in the ear may arise singly or in crops, and may be a.s.sociated with eczema of the meatus or with chronic suppuration of the middle ear. Pain is the chief symptom complained of, and it may be very acute. Deafness ensues when the meatus becomes completely blocked by the swelling. The boil occurs in the cartilaginous meatus, and it is to be borne in mind that the skin may present a normal appearance even when suppuration has occurred.
Palpation of the affected area with the probe causes intense pain.
Sometimes dema over the mastoid with displacement forwards of the pinna supervenes, and simulates acute inflammation of the mastoid.
_Treatment._--If seen in the earliest stages, an attempt may be made to relieve the pain by the application of a 20 per cent. menthol and parolein solution, or by the use of carbolic acid and cocain, 5 grains of each to a dram of glycerine. When suppuration has occurred, the best treatment is by early incision, transfixing the base of the swelling with a narrow knife and cutting into the meatus. If the tendency to boils persists, a staphylococcal vaccine will be found of value.
#Foreign Bodies.#--It is unnecessary to enumerate all the varieties of foreign bodies that may be met with in the ear. They may be conveniently cla.s.sified into the animate--for example maggots, larvae, and insects; and the inanimate--for example beads, b.u.t.tons, and peas.
Pain, deafness, tinnitus, and giddiness may be produced, and such reflex symptoms as coughing and vomiting have resulted.
The main practical point consists in identifying the body by inspection. The mere history of its introduction should not be taken as proof of its presence. In children it is advisable to give a general anaesthetic so that a thorough examination may be made with the aid of good illumination. If previous attempts to remove the body have caused dema of the meatal walls, and if the symptoms are not urgent, no further attempt should be made until the swelling has been allayed by syringing with warm boracic lotion, and by applying one or more leeches to the tragus. An attempt should always be made in the first instance to remove the body by syringing. It is rare to find this method fail. Should it do so, a small hook should be used, sharp or blunt according to the consistence of the body. Maggots, larvae, and insects should first be killed by instillations of alcohol and then syringed out.
AFFECTIONS OF THE TYMPANIC MEMBRANE AND MIDDLE EAR
#Traumatic Rupture of the Tympanic Membrane.#--Perforating wounds may result from direct violence caused by the patient--for example, in attempts to remove wax or foreign bodies, or by clumsiness on the part of the surgeon. It is also a comparatively common complication of fracture of the middle fossa of the base of the skull. More commonly, perhaps, the membrane is ruptured from indirect violence due to great condensation of the air in the external auditory meatus, following blows upon the ear, heavy artillery reports, or diving from a height.
The injury is followed by pain in the ear, often by considerable deafness and tinnitus, and bleeding is frequently observed. If early examination of the ear is made, coagulated blood may be found in the meatus or upon the membrane, or ecchymosis may be visible on the latter. A rupture in the membrane following indirect violence is usually lozenge-shaped. During inflation by Valsalva"s method the air may be heard to whistle through the perforation. In all such injuries the hearing should be carefully tested, and the possibility of an injury to the labyrinth investigated by means of the tuning-fork test.