Correlations between ultrastructural findings and electrocochleographic recordings in experimental aminoside intoxication.

Correlations are made between the electrocochleographic aspects and the ultrastructural findings in 60 guinea pigs intoxicated with either Gentamycin or Tobramycin. Small cochlear lesions are studied in order to identify the electrical aspect corresponding to the earliest anatomical cell alterations. The wave shape seems to be more important than the classical input-output functions as first signs of the inability of the organ of Corti to clear the aminoside antibiotics. The reversal of N1 and N2 and later the accentuation of P1, frequently correspond to early signs of cell intoxication such as disruption of the regular arrangement of the endoplasmic reticulum and proliferation of lysosomes. A similar situation may obtain in humans intoxicated with aminosides.