Electrocochleography in the Evaluation of Patients with Ménière's Disease/Endolymphatic Hydrops

Electrocochleography (ECochG) has evolved as an important tool in the diagnosis/assessment/monitoring of Ménière's disease/endolymphatic hydrops (MD/ELH). This manuscript provides an update on the use of ECochG for these purposes. The material presented includes descriptions of the components of the electrocochleogram; ECochG recording approaches and parameters; how to prepare for an exam, including subject/patient considerations; construction and placement of a tympanic membrane recording electrode; and interpretation the electrocochleogram. Various approaches aimed at improving ECochG's sensitivity and specificity to MD/ELH also are described. These approaches go beyond simple measurement of the now-conventional summating potential (SP)/action potential (AP) magnitude ratio to include the SP magnitude to tonebursts, the SP/AP area ratio, and the AP latency difference to clicks of opposing polarity.

Key Words

Action potential - auditory brainstem response - auditory evoked potentials - broadband click - cochlear microphonic - electrocochleography - extratympanic - Ménière's disease/endolymphatic hydrops - summating potential - toneburst - transtympanic - tympanic membrane - tymptrode