Interactions between the middle ear and the inner ear: bacterial products.
The round-window membrane (RWM) is extremely thin and is the only soft-tissue barrier between the middle ear and the inner ear. Under inflammatory conditions of the middle ear the various layers of the triple-layered RWM undergo characteristic changes parallel to the changes of the middle-ear mucosa. Several studies report that bacterial products, exo- and endotoxins, from bacteria invading the middle ear may result in profound inflammatory changes in the inner ear, followed by severe damage to the inner-ear function. The present review, in which we summarized experimental and clinical observations, on bacterial products in interactions between the middle and inner ear, focused on: 1. Bacteria and bacterial products in an inflamed middle ear that may influence inner-ear function. 2. RWM structure and RWM permeability under the influence of bacteria and bacterial products. 3. Morphological and functional inner-ear effects of bacterial infection of the middle ear, and the possible mechanisms involved. 4. Future studies to be directed in this field.
Hellström
S
S
Department of Otorhinolaryngology, University of Umeå, Sweden. sten.hellstrom@ent.umu.se
Eriksson
P O
PO
Yoon
Y J
YJ
Johansson
U
U
D000818:Animals; D001427:Bacterial Toxins / Q000633:toxicity*; D007758:Ear, Inner / Q000382:microbiology* / Q000473:pathology; D004432:Ear, Middle / Q000382:microbiology* / Q000473:pathology; D006801:Humans; D010033:Otitis Media / Q000209:etiology; D011008:Pneumococcal Infections / Q000473:pathology
D001427:Bacterial Toxins