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 |   Related post: already quoted there is some diflSculty in explaining the phenomenon ; why the bone-conduction is not always aug- mented by means used to relieve pressure on the labyrinth, as, for instance, pushing out a sunken drum-membrane by inflation, does not appear. If pressure is the sole cause of the deafness in such cases, it would seem that relief of press- ure should place the nerve in better condition to appreciate bone-conduction, as the aerial conduction has been im- proved. On the other hand, if the cause of the deafness exists in the badly vibrating middle-ear mechanism due to the crowding together of the ossicles, placing the membrana tympani on the stretch, then the improved bone-conduction resulting from inflation should be constant, which is very far from being the case. In this instance we adopt the theory that bone-conduction is improved Buy Myambutol or diminished by the good or bad vibratory condition of the middle-ear mechanism. Neither of these theories seems to be tenable. It may be worthy of remark that, from a theoretical point of view, we might expect weakened bone-conduction in every case of lowered hearing from any cause whatever. It is not in the least a matter of wonder that changes re- sult in cases of tolerably pure middle-ear disease, which pro- duce disturbances in the function of the acusticus, and con- sequently give the tuning-fork reaction of labyrinthine dis- ease. In any case of permanent impaction of the stapes in the oval window consequent on middle-ear disease there must needs be pressure on the perilymph. Thickening of the membrane of the round window will accomplish the same thing, but in a less degree. In syphilitic middle-ear disease we are likely to have similar conditions, only greatly exaggerated, the tendency to inflammatory proliferation, as is well known, being much; stronger than in non-specific cases, and the structural changes will be proportionately greater. It may also ac- count for the prompt improvement in hearing under a rapid course of mercury. It is by no means denied, however, that the more usual syphilitic lesions are for the most part laby- rinthine. All of these conditions are likely, but are not certain, to result in weakened bone-conduction, and add the element of labyrinthine disease to the middle-ear affection. Summary. — I conclude that the greatest amount of bone-conduction proceeds from a normal ear closed, and that the principal diagnostic sign of labyrinthine disease appears in weakened bone-conduction. That the apparent increase of bone-conduction in mid- dle-ear disease will disappear when the test is made witb the ear closed, when it will be found not to exceed that of the normal ear. In those cases called " mixed " the bone- conduction will be found weakened when the test is made with the ear closed, although with both ears open the af- fected one may have better bone-conduction than its fellow. That, so far, it seems that the good or bad condition of the middle-ear mechanism has little influence on bone-con- duction. That the occasional phenomenon of intermittent bone- conduction can not be satisfactorily explained. That cases of pure labyrinthine disease can not always be distinguished from those of middle- ear aflfections with secondary labyrinthine changes by the tuning-fork^ and that the history of the cases must materially aid us in the dis- tinction. That the phenomenon of secondary labyrinthine changes in middle-ear diseases is easily explainable. That there are numerous exceptions to the rules for finding the best points on the head for eliciting bone-con- duction. That the bone-conduction is rarely or never of less thaa its proper ratio to aerial conduction. AN EXAMINATION OF THE EYES OF FIFTY CASES OF CHOREA OF CHILDHOOD. By G. E. DE SCHWEINITZ, M. D. (Univ. of Penn.), OPHTHALMIC SURGEON TO THE PHILADELPHIA HOSPITAL, TO THE CHILDREN'S HOSPITAL, AND TO THE INFIRMARY TOR NERVOUS DISEASES. The cases of chorea from which this study has been made have for the most part been those of patients in attendance at the clinics of Dr. S. Weir Mitchell, Dr. Wharton Sinkler, and Dr. William Osier in the Infirmary for Nervous Diseases- Certain results which should naturally be the outcome of the examinations which follow are not set down, because suflBcient time has not yet elapsed to render this possible. The following points have received special attention : The chromatic symmetry or asymmetry of the irides, the devel- Related links: Buy Ilosone, Buy Exelon, Buy Loperamide Online, Bimatoprost Ophthalmic Solution 0.03 Buy, buy xenical online australia, where can i buy clomid in the us, How To Get Acyclovir, Adefovir Dipivoxil Price, Panax Ginseng Extractum, buy celexa online uk
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