A possible mechanism of the formation of endolymphatic hydrops and its associated inner ear disorders

Dynamics in Endolymphatic Hydrops & Symptoms in Meniere's Disease After Endolymphatic Duct Blockage, Preliminary Results

“…This difference in hearing results could be explained by the effect of different operations because the action of EDB in treatment of MD is expected to be different from the traditional ES shunting/decompression procedures. Although an understanding of the physiologic mechanisms underlying Meniere's related vertigo and fluctuating hearing threshold is yet emerging, yet, a major body of evidence already exists that supports a direct link between hydrops and disordered auditory physiology (35) and abrupt development of hydrops was thought to play a pivotal role in the onset of vertiginous seizure (36), suggesting the therapeutic management of vertiginous seizer or acute aggravation of deafness in MD should be directed toward the control of acute development or exacerbation of EH (36), which is likely to explain why the decreased VHR was associated with reduction in the average number of spells and hearing threshold postoperatively in our study. An improvement of the average hearing threshold of 5.51 dB was also detected postoperatively, although it was not statistically significant between the before and after.…”

A comparison of endolymphatic duct blockage, endolymphatic sac drainage and endolymphatic sac decompression surgery in reversing endolymphatic hydrops in Meniere's disease

“…Since no further patients showed any reduction in the endolymph space at > 12 months following surgery-indeed, a recurrence of vestibular hydrops in one patient was detected in comparison with the results of Gd-MRI 2 weeks following surgery-a delayed effect for reducing EH was not found in EDD group. Although a precise understanding of the physiological mechanisms underlying MD-related vertigo has yet to be elucidated, vertiginous attack is considered to result from acute development or exacerbation of EH [ 22 ], suggesting that the reduced in EH was likely to have been associated with a reduction of spells. This hypothesis seems likely to explain how a complete control of vertigo was achieved in the patients in both the group with endolymphatic duct blackage and the group with endolymphatic sac drainage who exhibited a reversal of EH in the present study.…”

Modulation of hearing function following the downgrading or upgrading of endolymphatic hydrops in Meniere’s disease patients with endolymphatic duct blockage

“…In the present study, among patients with decreased EVVR, the average hearing threshold and -SP/AP ratio decreased significantly; among patients with an increased EVVR, the average hearing threshold and -SP/AP ratio tended to increase following surgery, as compared with the value prior to surgery ( Fig 7 ). These results showed a causative correlation between a disordered hearing function and EH [ 45 ], in which the reduction of EH is likely to decrease the direct mechanical impact of high endolymphatic pressure and reverse the displacement of the BM, leading to an improvement in hearing. On the contrary, the increased of endolymphatic volume may give rise to an increase in the displacement of the BM and result in hearing deterioration.…”