Politzer's text-book of the diseases of the ear and adjacent organs : for students and practitioners / translated at the request of Professor Politzer and edited by James Patterson Cassells.

Ádám Politzer

Date:: 1883

Credit: Politzer's text-book of the diseases of the ear and adjacent organs : for students and practitioners / translated at the request of Professor Politzer and edited by James Patterson Cassells. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

108/858 (page 88)

$^' n'^ ™^ Pathological Basis op the Obstacles to THE Conduction of Sound in the MiddleXr If we review the tissue changes of the linino- membranp of fh. middle ear, It will be seen that^nflammatorVoce^se^^^^^^ resolved without new formation of tissue, or^ tW eave b^^^^^^^ them organized, permanent, inflammatory producte iTthe fi case the function of hearmg wiU agamYecome Lmal on the oarSel''^!'^^^ (^-''^^1^ inflaZatioi ShearW will hi ' f^^'^ disturbance ! T!- r*^® greater, the more serious the obstacle to the conduction of sound produced by the inflammatory products ^.e., the more firmly the sound-condictmg structures are im ted to each other, and to the waUs of the tympanic cavity. Ihe membrana tyinpani also is often aftected by disease of the iStirf'^'T f T^^^ ^^^^ if pathological alterations, to be described more fully further on, are of less Sn^. 5^'''^' f]^?ctional disorders in general than those products of disease which impau^ the mobihty of the ossicula, yet tney are ol great importance, an ocular inspection of the mem- Drana tympam permitting in many cases a conclusion to be drawn as to the anatomical changes in the middle ear. ihe jDathological alterations which take place in the middle ear may be tabulated as follows : a. Obstacles to the Conduction of Sound by Pathological Changes in the Membrana Tyniimni. These are caused by: 1. Increase in buUc of the membrana tympani produced by {a) serous infiltration of the membrane ; {b) effusion in its layers, ending in the formation of abscesses, calcification and ossification; (c) formation of granulations, poly^Dous growths or interstitial new formation of connective tissue with condensation of the membrane. 2. Anomalies of tension of the membrana tympani, the tension being either increased or decreased. The membrane may be too tense, (a) in consequence of the impermeabihty of the Eustachian tube, the membrane being forced inwards by atmospheric pressure ; (b) by retraction of the tendon of the tensor tympani; (c) by abnormal adhesions of the membrana tymjDani with the ossicula or with the inner wall of the tympanic cavity; {d) by accumulation of interstitial exudations, and by dejDosits on the membrana tympani. The tension of the membrane is lessened—(a) by inflammatory softening; (b) by disturbance of its connections, by rupture, perforation and losses of substance ; (c) by total or partial atrophy of its layers, especially of the substantia propria; {d) by cicatricial formations; (e) by detachment of the membrane from the handle$