Neuro-otologic applications of simultaneous multi-channel auditory evoked response recordings

Multichannel auditory brain stem response (ABR) recordings were obtained in 75 acute, severely brain injured patients. The purpose of the study was to assess, in patients with varied neuro-otologic pathology, the clinical feasibility and value of measuring the ABR simultaneously with more than one electrode array. The use of alternative electrode arrays, in addition to the conventional (vertex to stimulus ipsilateral ear) array, augmented confident identification of wave components I through VI, and was particularly useful in patients with marked middle ear pathology which confounded ABR interpretation. The ABR recorded with an indifferent (noncephalic) reference electrode, e.g., was characterized by increased Wave V amplitude, and improved definition of Wave IV vs. V. Case studies are presented to illustrate neuro-otologic applications of the multichannel recording technique.