Effect of Artificial Endolymph Injection into the Cochlear Duct on Perilymph Potassium

2005 Fiscal Year Final Research Report Summary

• Project/Area Number: 16591714
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Otorhinolaryngology
• Research Institution: Kochi University
• Principal Investigator: KAKIGI Akinobu Kochi University, Medical School Hospital, Assistant Professor, 医学部附属病院, 講師 (60243820)
• Co-Investigator(Kenkyū-buntansha): TAKEDA Taizo Kochi University, Medical School, Professor, 医学部, 教授 (50115763)
• Project Period (FY): 2004 – 2005
• Keywords: Meniere's disease / potassium ion / endolymphatic hydrops

Research Abstract

The pathological feature of Meniere's disease is endolymphatic hydrops. However, the causes of symptoms during Meniere's attacks remain unclear. One hypothesis of the Meniere's attack is that endolymphatic hydrops causes perilymphatic potassium increase and the potassium has a toxic effect on the eighth nerve.^<1,2> The results from temporal bone histopathology of Meniere's disease that include the rupture of the Reissner's membrane support this hypothesis. If it is the case, high K^+ of endolymph should leak into scala vestibuli. The higher K^+ in scala vestibuli could propagate into scala tympani through the spiral ligament and, in apical regions, through the helicotrema. However, the cause of K^+ leakage from endolymph could occur not only from a rupture of the Reissner's membrane but also from a permeability change of the cochlear duct without rupture, suggested by observations that Reissner's membrane ruptures are not observed in all temporal bones following attacks. The purpose of this study is to investigate the relationship between endolymphatic hydrops and perilymphatic potassium under conditions without Reissner's membrane rupture.