CHAPTER X. INJURIES OF THE MEMBRANA TYMPANI. (Part 1)

CHAPTER X. INJURIES OF THE MEMBRANA TYMPANI. The diseases of the membrana tympani occur either as a result of an inflammation of the external auditory canal, or of the middle ear. I have not seen any cases of independent or primary myringitis, or inflammation of the drum membrane, such as are delineated with theoretical minuteness by some writers on otology. The anatomical structure of a membrane that has but one layer of tissue peculiar to itself, and that in its centre, but which is a direct uninterrupted continuation of the adjacent parts, precludes the idea of an inflammation that occurs primarily in this part. A glance at the nerve, lymph, and blood supply of the partition wall which is called the membrana tympani, shows that it has no independent nourish- ment, and strengthens the view that the inflammations that attack it, must be of a secondary character. I have therefore discarded the term myringitis, or inflammation of the drum membrane, except as the name of one of the symptoms of otitis externa or media, or to describe the inflammation pro- duced by injury. There is probably no independent disease called myringitis, in the sense that we speak of a keratitis or a retinitis. Dr. A. H. Buck* has recently reported a case of interlaniellar cyst of the membrana tympani, which might be supposed to be an independent disease of this part ; but the history shows that the patient was suffering, at the time of tire formation of the cyst, from chronic eczema of the auditory canal, which causrs the case to be one of extension of disease of the meatus to the drum- head. The membrana tympani is, however, subject to injury from explosions, or sadden and violent movements of the atmos- * Medical Record, vol. vii., p. 572. INJUEIES OF MEMBEANA TIMPANI. 223 phere, which cause the undulations to be condensed and forced inwards upon the drum-head. It may also be ruptured by the force of condensed air, as, for example, that which is found in passing through the lock of a caisson used in build- ing bridges. The membrana tympani may also be ruptured by blows upon the side of the head or upon the ear, or from direct injury by the striking of a sharp instrument directly upon the membrane, and so forth. The explosion of artillery is not apt to cause rupture of the drum-head. When we consider the number of persons who have been thus exposed to injury, it is somewhat surprising that no more have suffered from this cause. After diligent inquiry among army surgeons, I have heard of but very few cases of rupture of the membrana tympani occurring from this cause ; and although I have seen many patients who became partially deaf, from the exposures incident to cam- paigning, during our late civil war, I have as yet seen but one case, where a rupture of the drum membrane occurred from the explosion of artillery. The long-continued exposure to heavy firing often, and perhaps always, causes a temporary ringing in the ears, probably from concussion of the laby- rinth, and sometimes hemorrhage from the vessels of the mem- brana tympani, but very rarely is a rupture produced. The effects of the concussion do not always pass away, and some soldiers acquire a chronic inflammation of the internal and mid- dle ears from this cause, just as do boiler-makers, who work amid deafening noises. Ruptures from concussion do occur, however. I once saw a woman at the New York Eye and Ear Infirmary, who had suffered such an accident from the firing of a pistol near her ear ; and Dr. Hackley observed a similar result in an actor who was obliged to fire a pistol over his shoulder during a play. The power of the muscles of the Eus- tachian tube, which act very quickly, and force, as it were, a current of air in upon the drum membrane from the inner side, is probably that which counterbalances the effect of a sudden condensation of air upon the outer side. The little chink, which normally exists in the caliber of the tube, is also a source of pro- tection. Those persons who suffer a rupture of the drum-head from external concussions, probably have some catarrhal, affec- 224 EUPTUllE OF MEMBRANA TYMPANI. tion which, prevents the air from freely circulating in the tubes and the cavity of the tympanum ; for we can scarcely believe that so few would suffer this accident, were all drum membranes equally liable to it. During the heavy fighting of our civil war, infantry soldiers in the trenches were in the habit of lying down, while the artillery behind fired over their heads ; and yet, as I have found by inquiry, rupture of the membrana tym- pani was scarcely heard of. Gruber's experiments on the cadaver show that the resist- ing power of the membrane is very great. Dr. Schmidekarn assisted Professor Gruber* in these experiments, which proved, according to the former author, that the resisting power of the membrane was greater in man than in the other animals. It required a column of quicksilver of 143cm. high to rupture the ^membrana tympani of an ear that had lain in alcohol for a few weeks. The stapes and incus had been removed. The rup- ture was straight and parallel to the lower three-fourths of the anterior line of attachment of the malleus. In another case a drum-head, which exhibited the remains of a former inflammatory process, in the form of a false membrane, was not ruptured until a column of quicksilver 168cm. high, was used. Here again the rupture occurred on the anterior segment. Gruber also examined the resisting power of the drum-head by the following experiment : He introduced a catheter with a bulbous extremity into the Eustachian tube of a fresh subject, having a healthy membrana tympani, and fastened the catheter in the tube by means of a stout thread stuck through it. He then allowed a stream of air from a compression pump — air that had been condensed four or five fold — to pass suddenly into the tube, or after closing the tube by tying a cord about it, he stopped the external auditory canal by means of a gutta- percha plug, with a small tube in it, through which he allowed the compressed air to pass. Gruber was never able to break the membrane in this experiment. The gutta-percha plug with the tube was driven out of the canal, but the membrane was never ruptured. * Lehrbuch, p. 333. EUPTUEE OF MEMBEANA TYMPANI. 225 Professor Gruber saw a great many patients who were engaged in the battles of Schleswig-Holstein and Bohemia in 1864 and 1866, and although he examined nearly all the aural patients of the Garrison Hospital in "Vienna, he saw but one where the explosion of projectiles had caused a rupture of the drum-head. In this case the soldier was knocked sense- less by the explosion of a grenade, which killed two near him. "When he recovered his senses he was suffering from tinnitus aurium in the left ear, and was deaf on this side. Pain oc- curred, and in three weeks after, when he was seen by Dr. Gruber, he was found to have a roundish opening about one and a half lines in diameter, in the anterior and inferior seg- ment of the drum-head. The tubes were pervious, and there was no evidence that he had previously suffered from aural disease. This, however, was the only case among hundreds of soldiers that fought at Koniggratz, who had suffered the injury which has been detailed. Dr. Andrew H. Smith, one of my colleagues at the Man- hattan Eye and Ear Hospital, was the medical officer in charge of the men engaged in laying the foundations for the bridge from New York to Brooklyn over the East Biver, and had many opportunities of observing the effects of compressed air upon the membrana tympani. Through Dr. Smith's cour- tesy, I saw some cases that illustrate this subject ; and I here give from Dr. Smith's notes, one of rupture of the membrana tympani which occurred while the patient was passing through " the lock." Dr. Smith describes the case of rupture of the membrane as follows : " John H., on May 17th, the pressure being about 35 pounds to the square inch above the normal ; the patient was attacked while in the lock going down for the first time, by a severe pain in the right ear, followed by a slight dis- charge from the meatus. No sensation was felt as of anything giving way in the ear. He completed his watch, and then reported to me. On examination, the drum-head was found to be ruptured at its upper edge. The opening was nearly circular and rather less than a line in diameter. The patient preferred not to go on with the work, and he was not seen by me again." Dr. Smith believes that most of the men who suffered from aural trouble after having been in the caisson, had previously some impairment of the permeability of the Eustachian tubes. 15 226 EFFECTS OF CONDENSED AIR. The men under his care were " most strenuously " instructed not to enter the caisson unless they were able, when holding the nose and blowing forcibly, to feel the air enter both ears. Nevertheless, cases occurred in which this precaution was neglected, and the individual was, in consequence, caught in the lock unable to " change his ears."* Dr. Smith says that the structures within the tympanic cavity not being acted upon by the increased pressure, " are placed relatively in the same position as the skin under a cupping-glass," by the continued exposure to the effect of compressed air, when the Eustachian does not open, or rather, as we should say, when it does not act well, from swelling or thickening of its tissue. Then the intense congestion occurs, which may be followed by inflammation, finally result- ing in perforation of the membrane, as happened in one case reported by Dr. Smith in his paper. Politzer's method of inflating the ears was found very use- ful in treating these cases of simple congestion, which, if they had not been treated, would have resulted in tympanic inflam- mation and perforation of the drum-head. As an effect of the use of this method of treatment, many of Dr. Smith's men were enabled to continue at their work who could not have otherwise done so without danger. The treatment bepame very popular among the men, so that as many as four or five of them would come at Dr. Smith's visit to have their " ears blown out." I saw three or four of these cases of congestion of the tym- panic cavity, they having been sent to me by Dr. Smith, and was enabled to see the great advantage of skilled medical advice to these men. Many ears would certainly have been permanently injured had not Politzer's method been employed at an early stage of the trouble.? * This is the term used by the men to signify the operation of holding: the nose and blowing until the air is felt to enter the middle ear. This operation has to be constantly repeated while the air pressure is increasing in the lock, in order to relieve the pain resulting from the pressure upon the membrana tympani. In some persons the act of swallowing answers equally well. f Dr. Smith's paper on " The effects of High Atmospheric Pressure, includ- ing the Caisson Disease," received the prize of the Alumni Association of the College of Physicians and Surgeons for 1873, and will soon be published. My extracts are taken from the manuscript loaned to me by the author. EFFECTS OF CONDENSED AIR. 227 A gentleman who once consulted me in reference to what I deemed to be an incurable chronic catarrh of the middle ear, which had resulted in thickening and sinking of the drum- head, afterwards came to me with a perforation of the mem- brane of one side and discharge of pus from the tympanum, which he stated was caused by a visit to the caisson. The perforation soon healed, and the hearing was rather worse than before the accident. Dr. John Green,* of St. Louis, had previously to Dr. Smith made some observations upon " the physiology of the Eusta- chian tube, during a short exposure to an atmospheric pres- sure of sixty pounds to the square inch." Dr. Green's obser- vations were made while bridge-piers were being sunk to the rock underlying the bed of the Mississippi river at St. Louis in 1869-1870. The entrance to the chamber of condensed air was " through an air lock, or small chamber into which the condensed air could be admitted gradually, occupying, for the higher degrees of pressure, from four to ten minutes." The exit occupied about the same time. The accidents to the ears occurred, as in Dr. Smith's cases, while passing through this lock. Sudden chilling of the body from changes in temperature in the chamber were, according to Dr. Green, causes of catarrhs. This theory is rather more sufficient to explain the cases of tympanic congestion when the tube was not completely pervious, than the one of mechanical pressure, although undoubtedly both causes acted together in producing aural affections. Dr. Green notices an interesting phenomenon observed in coming out of the lock, which Dr. Smith also observed. There was a spontaneous escape of air through the Eustachian tubes in a succession of puffs, succeeding each other at intervals of fifteen or twenty seconds, independently of respiration, and absolutely without the concurrence of any muscular action. The phenomenon suggested to Dr. Green " the action of a lightly resisting valve, necessitating a slight but perceptive increase of pressure within the tympanic cavity, to open the * Transactions of the American Otological Society, 1870. 228 EFFECTS OF CONDENSED AIE. passage to the pharynx." Dr. Green observed several cases of rupture of the drum-head and acute catarrh occurring as a result of the unequal pressure, and of the exposure to an uneven temperature. Dr. A. Magnus,* of Konigsburg, investigated very carefully the behavior of the ear in condensed air, in 1863, while a rail- way bridge was building in his city. He proved that the in- jury to the ear was caused by pressure upon the membrana tympani, because when he plugged the auditory canal hermet- ically, no unpleasant sensations were felt, but when he re- moved the stopper the air streamed with a powerful current into the canal, and pain occurred very soon. The ear that was stopped remained without pain, and the Yalsalvian experi- ment soon relieved the pain in the uncovered one. Magnus also proved by an examination of ears when the pressure was being exerted, that the membrana tympani was actually pressed inward. The triangular spot was obliterated when the pres- sure was greatest and the pain severe. A patient without any membrana tympani, who was subjected to the condensed air, had no pain. Indeed, there was not a trace of an unpleasant sensation. The membrana tympani undoubtedly owes much of its resisting power, as Mr. Shrapnell pointed out, to the existence of a triangular membrane at its upper portion that is less tense and thick than the remainder of its structure, the so- called membrana flaccida, or Shrapnell' s membrane, which yields when undue pressure is brought upon it. The mem- brane has, perhaps, some additional defence in its oblique position in the canal, which causes a portion of it to be covered by the walls in such a way as not to receive the whole force of the column of compressed air.f The membrana tympani is perhaps more frequently injured by mechanical violence to the head or to the membrane itself. My friend Dr. Kobert E. Weir,:): Surgeon to the New York Eye and Ear Infirmary, has seen four such cases. In one the * Archiv fur Ohrenheilkunde, Bd. I., p. 27a \ The effects of compressed air upon the hearing power will be again alluded to in the chapter on Chronic Non-suppurative Inflammation. \ Verbal communication. INJUKIES OF MEMBIUNA TYMPANI. 229 drum-head was ruptured by a blow upon the head with the hand. In another, fragments of rock from a blast struck the head and ruptured the membrane. In the third case the injury was caused by a snow-ball striking the ear ; and in the fourth a hair-pin was accidentally forced through the part. In the first three, of Dr. Weir's cases, the rupture was slit- shaped, parallel and posterior to the handle of the malleus. I have now under my observation a gentleman of about fifty years of age, whose membrana tympani is said to have been ruptured when he was a small boy, by blows upon the side of his head, given by one of his teachers. The membrane is nearly entirely gone, and there is at times a purulent dis- charge from the tympanic cavity. Teachers and parents who have the bad habit of striking children unexpectedly to their little charges, should be warned of the danger of a box on the ear to the integrity of the organ. The membrana tympani is sometimes ruptured in attempts to remove foreign bodies, such as inspissated cerumen, and so on, by means of a probe, as has been seen in one of the pre- ceding chapters. The text-books of Toynbee and Von Troltsch record several interesting cases of injury to the drum-head by mechanical violence. The latter author relates one in which a young man, while going up a ladder, accidentally struck his ear against a blade of straw, which passed through the membrane and caused the severest pain, so that he nearly fainted. In one of Toynbee's* cases the rupture was caused by an unex- pected blow upon