title: Cisplatin ototoxicity, increased DPOAE amplitudes, and magnesium deficiency. Distortion product otoacoustic emissions.
abstract: Outer hair cell (OHC) metabolism is blocked by cisplatin. Concurrent changes in the renal handling of magnesium occur because of the damage cisplatin causes to the renal proximal tubule cells within the thick ascending loop of Henle. Although there is no evidence of cisplatin within the OHCs, there are significant levels of intracellular calcium, the antagonist to magnesium at the cell membrane. The OHC motile response is dependent on intracellular calcium. When the calcium current is suppressed by an antagonist, the extracellular OHC microphonic potential decreases. Magnesium deficiency is known to produce hyperexcitability within the central nervous system, including fatal audiogenic seizures. In addition, increases in the amplitude of the auditory brainstem response wave V occur with aminoglycoside therapy and magnesium deficiency. This paper illustrates the amplitude growth of distortion product otoacoustic emissions in two patients treated with cisplatin and explores the possible underlying reasons why this may be related to magnesium metabolism.
authors.affiliation: Mayo Clinic Scottsdale, Department of Otolaryngology, Head & Neck Surgery and Audiology, Arizona 85259, USA.
authors.forename: M J
authors.initials: MJ
authors.lastname: Cevette
authors.forename: D
authors.initials: D
authors.lastname: Drew
authors.forename: T M
authors.initials: TM
authors.lastname: Webb
authors.forename: M S
authors.initials: MS
authors.lastname: Marion
mesh_terms: D000230:Adenocarcinoma / Q000188:drug therapy / Q000556:secondary; D000328:Adult; D000970:Antineoplastic Agents / Q000009:adverse effects*; D001301:Audiometry, Pure-Tone / Q000379:methods; D015220:Calcium Channels / Q000378:metabolism; D002945:Cisplatin / Q000009:adverse effects*; D005260:Female; D018072:Hair Cells, Auditory, Outer / Q000187:drug effects* / Q000378:metabolism*; D006801:Humans; D008175:Lung Neoplasms / Q000188:drug therapy / Q000556:secondary; D008274:Magnesium / Q000627:therapeutic use; D008275:Magnesium Deficiency / Q000097:blood* / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D017084:Otoacoustic Emissions, Spontaneous / Q000187:drug effects*
chemical_list: D000970:Antineoplastic Agents; D015220:Calcium Channels; D008274:Magnesium; D002945:Cisplatin