The Permeability of the Round Window Membrane During Otitis Media

Auditory brain stem response changes after application of endotoxin to the round window membrane in experimental otitis media

“…It is possibly due to the presence of residual effusion overlying the membrane and a thickening of the RWM. Some of the different results between our and others' reports 4‐6,19‐21 might be due to the differences in materials and methods for the studies (i.e., the types and concentrations of substances to be passed, experimental otitis media models to be used, and the severity or duration of middle ear inflammation).…”

“…Goycoolea et al 21 observed an increased permeability of RWM to tritiated albumin in ETO‐OM in cats. On the contrary, Schachern et al 19 noted that passage of HRP through the RWM 3 days after ETO was similar to passage through the normal RWM, but the permeability was drastically reduced 1 week or more after ETO. Kim et al 20 observed that HRP traversed the RWM in normal guinea pigs and animals in the early stage of otitis media.…”

Spiral ligament fibrocyte-derived MCP-1/CCL2 contributes to inner ear inflammation secondary to nontypeable H. influenzae-induced otitis media

“…The round window membrane is the major route from the middle ear to the inner ear, since it is the only non-bony barrier between two structures. Its permeability is known to be affected by exposure to inflammatory conditions [29-31]. Inflammatory mediators or bacterial molecules such as endotoxin or exotoxin compromise the round window membrane permeability barrier and diffuse into the perilymph [9,32,33].…”

Sensorineural hearing loss in the acute phase of a single episode of acute otitis media

“…27 , 28 , 29 These mediators were mainly retrieved in the basal turn of the cochlea, which corresponds tonotopically to the high frequencies. 30 , 31 , 32 Clinically, translational studies have also positively correlated the region in which the main pathological alterations were found (basal turn of the cochlea) to the auditory frequencies most frequently affected by the AOM (high frequencies). 28 Another possible phenomenon that may lead to hearing loss at the early stage of AOM is the presence of transient endolymphatic hydrops, caused by pressure variations in the middle ear, round window membrane mobility alterations, or by the intracochlear inflammatory process.…”